0.9x + 20 = 830

Fill in the blank:

x=

We can solve this using inverse operations & “working backwards.”

Addition is the inverse to subtraction, so we’ll subtract 20 from 830.

830 - 20 = 810

From there, since division is the inverse to multiplication, we’ll divide 810 by .9 .

810/.9 = 900

Therefore, x is equal to 900.

You can check this answer by working through it forwards. (900 x .9 = 810, 810 + 20 = 830.)

Hope this helped! :)