Question

which expression is equivalent to 6x2 – 19x – 55? (2x – 11)(3x 5) (2x 11)(3x – 5) (6x – 11)(x 5) (6x 11)(x – 5)

Answer 1

$6x^{2} -19x-55 \\ =6 x^{2} -30x+11x-55 \\ =6x(x-5)+11(x-5) \\ =(6x+11)(x-5)$

Answer 2

Answer: (6x + 11)(x – 5)

Explanation:

In order to see which expression is equivalent to

$6x^2 -19x-55$ (1)

Let's solve each individual expression separately:

1) $(2x - 11)(3x + 5)=6x^2 -33 x +10 x-55=6x^2 -23 x -55$ --> NO

2) $(2x + 11)(3x - 5)=6x^2 +33 x -10 x-55=6x^2 +23 x -55$ --> NO

3)  $(6x - 11)(x + 5)=6x^2 -11 x +30 x-55=6x^2 +19 x -55$ --> NO

4)  $(6x + 11)(x - 5)=6x^2 +11 x -30 x-55=6x^2 -19 x -55$ --> YES

So, the choice that corresponds to eq.(1) is the last one:

(6x + 11)(x – 5)