The sum of the measures of angle X and angle Y is 90. If the measure of angle X is 30 less than twice the measure of angle Y, what is the measure of angle X?
20°
35°
50°
65°

Question

The sum of the measures of angle X and angle Y is 90. If the measure of angle X is 30 less than twice the measure of angle Y, what is the measure of angle X? 
20°
35°
50°
65°

mathstudent55 · Answer

x = 2y - 30
y + 2y - 30 = 90
3y = 120
y = 40
x = 2(40) - 30
x = 50

anonymous · Answer

where did you get the extra y?

mathstudent55 · Answer

The problem states the sum of the measures of x and y is 90. One angle is y. The other angle is x which is 2y - 30. When you add angle y to angle 2y - 30 you get 
         (y)          +            (2y -30)             =   90
     -------                  ---------              ----
    this is y                     this is x                  sum

anonymous · Answer

oh ok :) i see it now Thanks soo much

mathstudent55 · Answer

You're welcome.