Answer: 12a=48
Step-by-step explanation:
4a+6b=10
4a=10-6b
a=(10-6b)/4
a=(5-3b)/2
2a-4b=12
2((5-3b)/2)-4b=12
(5-3b)-4b=12
5-7b=12
-7b=7
b=-1
2a-4(-1)=12
2a+4=12
2a=8
a=4
a=4, b=-1
12a=48