Question

Solve p=10a+3b for a

Answer 1

Move b to the left.
-3b+p=10a
Divide all terms by 10
-3/10b + 1/10p= a

Rearrange
a= -3/10b + 1/10p

Answer 2

p=10a+3b
10a = 3b - p
a = (3b-p) / 10

hope it helps