How to write expressions and equations - Algebra 1

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Question

(9_x_2 – 1) / (3_x_ – 1) =

Answer

It's much easier to use factoring and canceling than it is to use long division for this problem. 9_x_2 – 1 is a difference of squares. The difference of squares formula is a_2 – b_2 = (a + b)(ab). So 9_x_2 – 1 = (3_x + 1)(3_x – 1). Putting the numerator and denominator together, (9_x_2 – 1) / (3_x_ – 1) = (3_x_ + 1)(3_x_ – 1) / (3_x_ – 1) = 3_x_ + 1.

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Question

Simplify the following equation.

Answer

We can simplify the natural log exponents by using the following rules for naturla log.

Using these rules, we can perform the following steps.

Knowing that the e cancels the exponential natural log, we can cancel the first e.

Distribute the square into the parentheses and calculate.

Remember that a negative exponent is equivalent to a quotient. Write it as a quotient and then you're finished.

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Question

Identify the real part of

Answer

A complex number in its standard form is of the form: , where stands for the real part and stands for the imaginary part. The symbol stands for .

The real part in this problem is 1.

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Question

Divide:

Answer must be in standard form.

Answer

Multiply both the numerator and the denominator by the conjugate of the denominator which is resulting in

This is equal to

Since you can make that substitution of in place of in both numerator and denominator, leaving:

When you then cancel the negatives in both numerator and denominator (remember that , simplifying each term), you're left with a denominator of and a numerator of , which equals .

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Question

Answer






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Question

Write in simplest form:

Answer

Rewrite, then distribute:

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Question

Translate this sentence into a mathematical equation:

Three less than five times a number is the same as two more than twice that number.

Answer

Three less than five times a number is the same as two more than twice that number.

Let the number be .

"Three less than five times a number" translates into .

"Is the same as" means equal to or "".

"Two more than twice that number" means .

Putting these together gives:

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Question

Rewrite the expression in simplest terms.

Answer

Here is the expression given: .

To simplify, follow the order of operations.

Distribute through the terms in the inner parentheses:

Now distribute into the terms of the remaining parentheses. Remember that multiplied by itself produces , but multiplied by produces :

Complete the multiplication to finish expanding:

Add like terms to reach the answer:

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Question

Rewrite the expression in simplest terms, where is the imaginary number .

Answer

Writing this expression in simplest terms can be achieved by first factoring the radical into its smallest factors.

Multiplying the two together results in . Multiplying this by (which is simplified to ) results in the answer .

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Question

Rewrite the equation for in terms of .

Answer

The goal in expressing in terms of is to isolate on one side of the equation. One way to do this is to factor out of the fraction on the right side of the equation, then divide the entire equation by the fraction that remains after factoring. Remember that dividing by a fraction is the same as multiplying by the reciprocal of that fraction.

The left side of this equation will simply resolve into , although there are still variables on the right, so this is not yet in terms of . The right side resolves based on the rules for multiplying and dividing variables with exponents (add the exponents of like variables being multiplied, subtract the smaller exponent from the larger in the case of division, and change the variable to a if the resulting exponent is ).

Since there is still a in the numerator on the right side of the equation, we will need to divide both sides of the equation by .

We have no solved for the reciprocal of in terms of . We simply flip both sides of the equation to get our answer.

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Question

Mr. Wiggins does not have enough books for all the students in his algebra class. He has 20 students, 10 textbooks, and 16 workbooks. He wants to divide his students into work groups according to the following rules:

- Every student must work in a group of 2 (a pair) or 3 (a trio).

- Every Pair or Trio must have at least 1 textbook and at least 2 workbooks.

How many pairs and trios should Mr. Wiggins divide his students into if he wants to have as many pairs as possible while following these rules?

Answer

The conditions of Mr. Wiggins's problem can be expressed with an inequality and an equation to narrow down the number of pairs and trios that meets his conditions.

First, since each pair or trio must have at least workbooks, dividing the total workbooks into sets of means that there cannot be more than pairs and trios total. This can be expressed in the following inequality where is the number of pairs and is the number of trios.

Since each student must be in a pair or trio, we can set the number of total students () equal to the number of students in pairs () plus the number of students in trios ().

To satisfy this inequality and this equation while maximizing (since Mr. Wiggins wants "as many pairs as possible"), start by substituting the maximum number of pairs () for , then work downward.

pairs would mean trios, according to the inequality . This does not satisfy the equation . Essentially, even though all of the workbooks are used, not all of the students have been accounted for. Continuing this pattern for , the sets , , , and satisfy the inequality, but they do NOT satisfy the equation.

satisfies the inequality and the equation, so the answer is pairs and trios.

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Question

Equations of a line can be represented as follows:

(1) (standard form)

(2) (slope-intercept form)

(3) (point-slope form)

Which of the following lines has

Various_lines

Answer

The equation of line is

Hence

and the

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Question

For the given equation determine the slope:

Answer

By changing the equation to slope intercept form we get the following:

Hence the slope is

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Question

What is the slope and the and intercepts of a line which passes through and ?

Answer

For a vertical line e.g. , and

This line does not intersect the and hence there is no .

Since the line passes through hence the -intercept .

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Question

A car travels at a speed of 60 miles per hour. It is driven for 2.5 hours. How many miles does it travel?

Answer

To solve this problem, you need to construct an algebraic equation. If is the distance traveled, then must equal to the speed multiplied by the time travelled. In this case, , which gives you a result of 150 miles.

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Question

Write the equation of a line with a slope of

and passes through the point .

Answer

Here we use the point-slope formula of a line which is

By plugging in , , and values we get the following:

which is equal to

When the above is simplified we get:

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Question

Complete the missing information for the equation of the following line

and determine which one of the coordinates is not a solution to the above equation.

Answer

Replacing with , one gets which tells us that is not a solution.

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Question

Convert the following into the standard form of a line:

Answer

Multiplying each term of the given equation by the denominator of the slope which is 5 one gets :

which can be written as

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Question

Find the equation of a line parallel to

and passes through .

Answer

The equation of a line parallel to the given line must be of the form:

Since the line passes through ,

we can calculate by replacing with 2 and with 1 which gives us the following

Solving for gives us the following equation

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Question

Find the equation of a line perpendicular to

and passes through

Answer

The slope of a line perpendicular to

which has a slope of , is the negative reciprocal of .

Hence we get

Replacing and with the given point we get

Solving for we get

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