2/3x - 7 = 17
First add 7 to both sides because that's the inverse
2/3x -7 = 17
+7 +7
2/3x = 24
Then you multiply the remaining numbers by 3 because that's the inverse of division
3(2/3x) = 3(24)
2x = 72
Then you divide by 2 to get the x alone
2x = 72
---- ----
2 2
x = 36
That's your answer