Respuesta :

subtract 5 from both sides
a/-8 = 4/7 - 5

simplify 4/7 - 5 to 31/-7
a/-8 = 31/-7

multiply both sides by 8 
-a = 31/-7 x 8

simplify 31/7 x 8 to 248/7
-a = 248/7

multiply both sides by -1.
The answer is a = 248/7

The words are the explanations of the steps and the dark bolded words are the work shown for each step.