Question

4x2 + 19x-5
Which two binomials are factors of the trinomial?

Answer 1

The factors are (4x-1)(x+5).

Explanation:

4x^2+19x-5

Break the middle term:

First multiply the coefficient of first term by the constant.

4*5=20

Now find any two numbers whose product = 20 and whose sum is equal to the middle term.

20*1 = 20

20-1 = 19

Now break the middle term:

4x^2+20x-x-5

Now group the first two terms and last two terms:

(4x^2+20x)-(x+5)

Now take the common from each group.

4x(x+5)-1(x+5)

(4x-1)(x+5).

Thus the factors are (4x-1)(x+5).....

Answer 2

(4x -1 ) ( x +5 )

Explanation:

4x2 + 19x-5

(4x ) ( x )

We need to get -5 The factors are -1 and 5 and 1 and -5

4*5 = 20

so the 5 will be on the outside We do this because we have +19 on the inside

(4x -1 ) ( x +5 )

Lets check

FOIL

4x^2 +20x -x -5 = 4x^2 +19x-5