Answer:
x = 12; y = 7.5
Explanation:
The arrows on the lines that appear to be parallel mean the lines actually are parallel. The square corner at bottom right means that angle is a right angle, 90°. Since the lines are parallel, the measures of angles made by the right-angle transversal are all equal and all have measure 90°.
That is ...
(12y)° = 90°
90/12 = y = 7.5 . . . . . divide by 12°, the coefficient of y
Using this value in the expression for the corresponding 90° angle, you get ...
(5x +4·7.5)° = 90°
5x = 60 . . . . . . . . . . divide by °, subtract 30
60/5 = x = 12 . . . . . .divide by the coefficient of x
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For this problem, you are supposed to realize that corresponding angles have the same measure (where a transversal crosses parallel lines) and that all the angles are 90° (when lines meet at right angles).