Question

21x + 7 22x + 2 180

Answer 1

Answer:

x = 5

Explanation:

If the angle are parallel:

step 1:

21x + 7 = 22x + 2

21x - 22x = 2 -7

-x = -5

x = 5

finding upper angle, then when both lies on straight line equals to 180°

step 2:

180 = (180 - 22x - 2 ) + 21x + 7

180 = 180 - 2 + 7 - 22x + 21x

180 = -x  185

-5  =  -x

x = 5

Answer 2

Solution:

Note that:

• 21x + 7 = 22x + 2 (Vertically opposite angles)

Solve the equation to find the value of x.

• 21x + 7 = 22x + 2
• => -2 + 7 = 22x - 21x
• => 5 = x

The value of x is 5.