Question

Find the pair of numbers that completes the factorization. x^2 - 3x - 40 = (x +?)(x-?)

a- 5,8

b- 4,10

c- 10,4

d- 8,5

Answer 1

Consider the form
`x^2+bx+c`. Find a pair of integers whose product is
`c` and whose sum is
`b`. In this case, whose product is -40 and whose sum is -3.

`\longrightarrow\boxed{\bold{(-8,5)}}`

Write the factored form using these integers.

`(x-8) \ (x+5)`

Answer 2

answer

a. 5,8

explanation

use numbers in each answer choice

+5 * -8 = - 40

+5 -8 = -3