Question

What is the measure of angle 7?

Answer 1

m<1 = m<4 by vertical  angles theorem

3x + 10 = 4x - 15

-1x = -25

x = 25

m<1 + m<7 = 180 if parallel alternate interior angles supplementary

3x + 10 + m<7 = 180

3(25) + 10 + m<7 = 180

75 + m<7 = 180

m<7 = 105°

Hope this helps! ;)