How many solutions are there to: x2 – 9 = 0

Two consecutive negative odd numbers have a product of 15. What is the sum of the two numbers?

What is the difference of the values of x that satisfy

4_x_2+ 3_x_ – 1 = 0?

2_x_ + y = 1

What is the slope and the y-intercept of the given equation, respectively?