Answer:
x = 17
Explanation:
The two given angles are supplementary angles, but also all angles on a straight light must add up to 180°:
3x + 14 + 7x - 4 = 180
Add like terms
3x + 7x + 14 - 4 = 180
10x + 10 = 180
Subtract 10 from both sides to isolate 10x:
10x + 10 - 10 = 180 - 10
10x = 170
Divide both sides by 10:
10x ÷ 10 = 170 ÷ 10
x = 17
Hope this helps!