Question

Which of the following is a factor of 8x2 + 21x + 10?

A) 2x + 5
B) 4x + 5
C) x + 2
D) None of the above

Answer 1

C) x + 2

Explanation:

we are given

`8x^2+21x+10`

We can split 21

`21=16+5`

`8x^2+(16+5)x+10`

`8x^2+16x+5x+10`

now, we can use grouping method

`(8x^2+16x)+(5x+10)`

now, we can factor it

`=8x(x+2)+5(x+2)`

`=(8x+5)(x+2)`

we can see that x+2 factor only maches