Okay, so to start, the bottom line equals 180°, so the two angles combined must equal that, right?
Next, come up with the equation:
![(3x + 2) + (6x - 20) = 180](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xaeu2emor0puubvz5001i2gy3c7qv6uglv.png)
After that, you can combine the like terms to simplify it a little:
![9x - 18 = 180](https://img.qammunity.org/2020/formulas/mathematics/middle-school/tyzs8kj6v8h0np7sic4t3gt57opg5o43lw.png)
From there, add the 18 to both sides to cancel it out, which leaves you with:
![9x = 198](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dtqh4hwe43lia694fx0wbbt1wtfujqxb7r.png)
Then just divide 198 by 9, and you'll get what X equals.
Hope it helps!