How to add rational expressions with a common denominator - PSAT Math
Card 0 of 3
Simplify the following rational expression: (9x - 2)/(x2) MINUS (6x - 8)/(x2)
Simplify the following rational expression: (9x - 2)/(x2) MINUS (6x - 8)/(x2)
Since both expressions have a common denominator, x2, we can just recopy the denominator and focus on the numerators. We get (9x - 2) - (6x - 8). We must distribute the negative sign over the 6x - 8 expression which gives us 9x - 2 - 6x + 8 ( -2 minus a -8 gives a +6 since a negative and negative make a positive). The numerator is therefore 3x + 6.
Since both expressions have a common denominator, x2, we can just recopy the denominator and focus on the numerators. We get (9x - 2) - (6x - 8). We must distribute the negative sign over the 6x - 8 expression which gives us 9x - 2 - 6x + 8 ( -2 minus a -8 gives a +6 since a negative and negative make a positive). The numerator is therefore 3x + 6.
Compare your answer with the correct one above
Simplify.
Simplify.
Same denominator means you add straight across the numerators, keeping the denominator the same.
Add like terms.
Final Answer.
Same denominator means you add straight across the numerators, keeping the denominator the same.
Add like terms.
Final Answer.
Compare your answer with the correct one above
Simplify.
Simplify.
Check for same Denominator
Add like terms
Check for GCF or if the expression can be factored
After factoring, divide out like terms. 
Final Answer
Check for same Denominator
Add like terms
Check for GCF or if the expression can be factored
After factoring, divide out like terms.
Final Answer
Compare your answer with the correct one above