A) 3x + 5 + y + 20 = 180
B) x + 15 + 4y -15 = 180
A) 3x + y = 155
B) x + 4y = 180
multiplying B) by -3
B) -3x -12y = -540 than adding this to A)
A) 3x + y = 155 equals
-11y = -385
y = 35 then putting this into equation A)
A) 3x + 5 + 35 + 20 = 180
3x = 120
x = 40
