Question

Find the value of x.

70


20


38


55

Answer 1

x = 20

Explanation:

Since one part of the straight angle = 90°, then

4x - 10 + x = 90, that is

5x - 10 = 90 ( add 10 to both sides )

5x = 100 ( divide both sides by 5 )

x = 20