Question

If QRST is a rectangle, find the value of x if angle Q is equal to 5x+30

Answer 1

If QRST is a rectangle then Q = 90°.

Threfore

5x + 30 = 90    |subtract 30 from both sides

5x = 60    |divide both sides by 5

x = 12

Answer 2

A rectangle is a four-sided flat shape where every angle is a right angle (90°). 

$QRST = 90^0$ 

$5x + 30 = 90$   

$5x = 60$    

$5x = 60 / 5$

$x = 12$