Respuesta :

Answer:

Correct answer is m = -3

Step-by-step explanation:

First you must to multiply two binomials:

(mx + 8) (2x - 4) = 2mx² - 4mx + 16x - 32 = 2mx² + (16 - 4m) x - 32

After that you equalize this expression and given expression

- 6x² + 28x - 32 = 2mx² + (16 - 4m) x - 32

After that you equalize the coefficients with the same monomials:

-6 = 2m  and 28 = 16 - 4m

m = -6/2 = - 3 and check in another

28 = 16 - 4 (-3)  => 28 = 16 + 12 = 28  => 28 = 28  identity is correct

God with you!!!