Need Story problem help!

How old am i if 200 reduced by 2 times my age is 30?

30 = 200 - 2*age

30-200 = 200 - 2*age - 200 (subtract 200 from both sides, to isolate "age".)

30-200 = -2*age (200 - 200 = 0; remove the |200|'s from the left side.)

-170 = -2*age (subtract 200 from 30)

-170/-2 = -2*age/-2 (divide each side by -2, to isolate "age".)

170/2 = 2*age/2 (-1/-1 = 1/1; remove negative signs.)

170/2 = age (2/2 = 1/1 = 1; remove the numerator and denominator from the right side.)

Solve: age = 170/2

200 - 2x = 30

170 = 2x

x = 170/2 = 85

You are old!