Question

What is the value of x?
40
20
12
At
P60°
8x-4
a
b

Answer 1

x = 8

8x - 4 = 60
first, add 4 from both sides of the equation
8x - 4 + 4 = 60 + 4
-4 + 4 = 0 so that cancels out, leaving
8x = 64
now divide by 8
8x/8 = 64/8
8/8 = 1, and 1x is just x so that cancels out, leaving
x=8

Answer 2

8x - 4 = 60 (alternate angles, parallel lines a and b)

8x = 64

x = 8