5a - 10 * 3 = 45
5a - 30 = 45
5a = 75
a = 75 : 5
a = 15
If b = 3, and 5a - 10b = 45. Then "a" must be......
Okay, so let's plug in what we know: 5a - 10 x 3 = 45 or 5a - 30 = 45
We now know that 5a = 30 + 45 or 5a = 75
Then, divide: 75 / 5 = 15
a = 15!
