How do you write the fraction for 20/10 as a mix

Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 4p cubedplusx squaredequals38 comma 400. determine the rate at which sales are changing at a time when xequals80, pequals20, and the price is falling at the rate of $.20 per week.

Point r divides in the ratio 1 : 3. if the x-coordinate of r is -1 and the x-coordinate of p is -3, what is the x-coordinate of q? a. b. 3 c. 5 d. 6 e. -9

What is the expression in factored form? 225x^2 - 144 a. 9(5x+4)^2 b. 9(5x-4)^2 c. 9(4x+5)(4x-5) d. 9(5x+4)(5x-4)