Answer:
b=7,A=19
Explanation:
A=2b+5
a-b=12
2) make both equations equal to 'a' by adding b on both sides so
a=2b+5,a=b+12
since both equations are equal to a, they are equal(is a=b then b=c property)
2b+5=b+12
this is a start, you can finish by combining the like terms and moving them to one side to get b=7 and a=19
HOPE THIS HELPS!!!