Question

PLS HELP!!!!!!!!!!!!!!!!

Answer 1

second option, (u - 12 - 3b)/4

Explanation:

isolate the "a" by bring each term to the other side, and finally div by 4

u = 12 + 4a + 3b

u - 12 = 4a + 3b

u - 12 - 3b = 4a

(u - 12 - 3b)/4 = a