Question

PLEASE HELP ME ON THIS MATH PROBLEM! I need an explanation

Answer 1

s. -30

Explanation:

All the angles in a triangle equal 180 so:

-2x - x + 90 = 180

add like terms

-3x + 90 = 180

subtracts 90 from both sides

-3x = 90

divide both sides by -3

x = -30