Respuesta :

multiply both sides by 4

-20 = 8m + 12

subtract both sides by 12
-32 = 8m

divide both sides by 8

m= -4 
apologiabiology
multiply by 4 to get rid of fraction
-20=8x+12
subtract 12
-32=8x
divide by 8
-4=x

x=-4

(oops it's supposed to be m instead of x)