Question

What is the value of x?

Answer 1

100 + x-4 +3x =180
x = 21
hope it help

Answer 2

Put all the angles = 180 (for a triangle's sum is 180 degrees)

x - 4 + 100 + 3x = 180

Add numbers (& common variables) together

3x + x + 100 - 4 = 180

4x + 96 = 180

isolate the x, subtract 96 from both sides

4x + 96 (-96) = 180 (-96)

4x = 180 - 96

4x = 84

isolate the x, divide 4 from both sides

4x = 84

4x/4 = 84/4

x = 84/4

x = 21°

hope this helps