Question

If the product of 5x+1 and 2x-3 was placed in ax^2+bx+c form, what would the value of a+b+c equal? Show how you arrived at your answer.

Answer 1

`(5x+1)(2x-3)=5x(2x-3)+1(2x-3)=10x^2-15x+2x-3=10x^2-13x-3`
`by\text{ comparison of corresponding terms of }10x^2-13x-3`

with

`ax^2+bx+c`

we have

a=10,b=-13,and c=-3

Therefore

a + b + c = 10 + (-13) + (-3) = 10 - 13 - 3= -6

That is

a + b + c = -6