Answer:
see below
Explanation:
CM is the bisector of ∠AMB
bisector means divide into two equal parts.
so x + 20 = 3x - 40
solve for x:
- x + 20 = 3x - 40 (combine similar terms)
- 20 + 40 = 3x - x (simplify)
- 60 = 2x (divide 2 both sides)
- x = 60/2
- x = 30
now substitute x=30 back into the equation
- x + 20 = 3x - 40
- 30 + 20 = 3(30) - 40
- 50 = 90 - 40
- 50 = 50 ------>> both are equal