Michael is 4 times as old as Brandon and is also 27 years older than Brandon. How old is Michael?

Let M mean Michael, and B mean Brandon, when write two equations:

M = 4B

B = M - 27

Replace the B in the first equation with what it is equal to in the second equation:

M = 4 (M - 27)

Distribute

M = 4M - 108

Subtract 4M from both sides

-3M = - 108

M = 36

Now put that back into the equation for B.

B = M - 27

B = 36 - 27

B = 9

So, Brandon is 9 and Michael is 36.