Respuesta :

Equanimity
Since B=3, we'll plug in 3 for B.
5a - 10(3) = 45.
Multiply 3 by 10 since it was "10b".
5a -30 = 45
Add 30 to each side to get 5a by itself.
5a = 75
Divide by 5 on each side.
a = 15
I hope this helps!