Answer:
EITHER x = 7
OR x = 14.5
Explanation:
When you have parallel lines and there's a third line crossing them, that makes 8 angles. 4 of these angles are ALL THE SAME MEASURE. and the other 4 angles are another number, but also ALL THE SAME MEASURE. And the two numbers add up to 180.
We kind of need to know where in the lay out of all 8 angles where are the ones you are working on. Because they are either the SAME VALUE or THEY ADD UP TO 180°
If they are the same, you set them equal to each other:
7x - 4 = 5x + 10
Subtract 5x
2x - 4 = 10
Add 4
2x = 14
Divide by 2
x = 7
OR
They add up to 180°
7x - 4 + 5x + 10 = 180
Combine like terms
12x + 6 = 180
Subtract 6
12x = 174
Divide by 12
x = 174/12 = 14.5