Question

Using the picture below, write and solve an equation to find x.
5x+10°
7x-30°

Answer 1

x=20

Explanation:

5x+10=7x-30

-5x. -5x

10=2x-30

+30 +30

40=2x

20=x

Answer 2

x = 20°

Explanation:

Vertically opposite angles are angles that are formed when two intersecting lines create opposite angles at a common vertex.

In other words, vertically opposite angles are the two angles that are directly across from each other when two lines intersect.

Vertically opposite angles are equal.

So,

5x + 10° = 7x - 30°

Subtract 5x on both sides:

5x + 10° - 5x = 7x - 30° - 5x

10° = 2x - 30°

Add 30° on both sides:

10° + 30° = 2x - 30° + 30°

2x = 40°

Divide both sides by 2.

`\sf (2x)/(2)=(40^\circ)/(2)`

x = 20°

Therefore, the value of x is 20°