On the very top right of the calculator you will see some lines click those lines and you will see a section with multiple options click fractions and voila
1.(2/3)x +50=330
2. (2/3)x =280
3. x = 280 / 2/3
4. x = 280 * 3/2
or
5. x = 280 * 1.5
6. x = 420
Therefore, the answer is 420 :)
