Question

If c(x) = 4x – 2 and d(x) = x2 5x, what is (cd)(x)? 4x3 18x2 – 10x x2 9x – 2 16x2 4x – 6 4x2 20x – 2

Answer 1

the main formula is (cd)(x)=c(x).d(x) 
If c(x) = 4x – 2 and d(x) = x2 + 5x
so  (cd)(x) = (4x – 2)(x2 + 5x)=4x^3+20x²-2x²-10x=4x^3+18x²-10x
so the answer is A: 4x^3+18x²-10x

Answer 2

Answer:

Option 1st is correct.

$(cd)(x) = 4x^3+18x^2-10x$

Step-by-step explanation:

Given the functions:

$c(x) = 4x-2$

$d(x) = x^2+5x$

We have to find $(cd)(x)$.

$(cd)(x) = c(x)d(x)$

then;

$(cd)(x) = (4x-2)(x^2+5x) = 4x(x^2+5x)-2(x^2+5x)$

Apply distributive property i. e $a \cdot (b+c) =a\cdot b+ a\cdot c$

$(cd)(x) = 4x^3+20x^2-2x^2-10x$

Combine like terms ;

$(cd)(x) = 4x^3+18x^2-10x$