Respuesta :

5a - 4a = 8
a = 8

All you needed to do is combine like terms, in this case by subtracting, and you have your answer right after doing so.
Problem: 5 a – 4 a = 8

REMEMBER- you can do anything with an equation as long as you do everything on both sides. 

5 a – 4 a = 8

lets first subtract, 5 a from 4 a (it is possible if the units are the same)

1 a = 8

1 a can be just simplified to a (because whatever number multiplied by 1 will still be equal to the same number)

There fore the correct answer is: a = 8