Question

Consider the following formula: y = 3 ( x + 5 ) ( x - 2 ) Which of the following formulas is equivalent to this one?
A. y=3x2+9x-30
B. y=x2+3x-lO
C. y=3x2+3x-lO
D. y=3x2+3x-30

is there someone that could show the work on figuring this one out so that I get a good idea to solve questions like this. also if anybody knows the name of this type of math problem could you give me a reference to study more like this. I know I just posted this earlier but the answer of the question doesn't do me much justice.

Answer 1

3(x^2+3x-10)
3x^2+9x-30

Answer 2

(x+a)(x+b)=x^2+(a+b)x+a*b
(x+a)(x-b)=x^2+(a-b)x-a*b