24)
<3 + <4 = 180 (supplementary angles)
25)
m<1 + m<2 = 180 (supplementary angles, sum = 180)
4x + 12 + 7x + 3 = 180
11x + 15 = 180
11x = 165
x = 15
So
m< 1 = 4x + 12 = 4(15) + 12 = 72°
m<2 = 7x + 3 = 7(15) + 3 = 108°
m<3 = m<1 (vertical angles)
6y = 72
y= 12
Answer
x = 15 ; m< 1 = 72°, m<2 = 108° and y = 12