Step-by-step explanation:
Straight line = 180 °
5x + 78 = 180
5x = 180 - 78
5x = 102
x = 20.4
and y = 78 ° because y is an opposite angle of 78 °
26.25$ you simply multiply 3 time 7.50 to get 22.5, you then divide 7.50 by 2 to get 3.75 once you add those together you get 26.25$
Step-by-step explanation:
i think a is the answer of this question.