Question

What is the value of x?

Answer 1

40° and 115°

Explanation:

x+3x-5+25°=180°(angle on a straight line)

4x+20=180°

4x=180°-20

4x=160°

x=160/4

x=40°

The other angle

3x-5=3(40)-5

120-5=115°

total

40°+25°+115°=180°

Answer 2

x = 15

Explanation:

the exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.

3x - 5 is an exterior angle of the triangle, then

3x - 5 = x + 25 ( subtract x from both sides )

2x - 5 = 25 ( add 5 to both sides )

2x = 30 ( divide both sides by 2 )

x = 15