Answer:
40°
Step-by-step explanation:
Given l \\ m,
m∠13 = m∠7 (alternate interior angles)
m∠13+m∠15 = 180° (Sum of angles in a straight line)
[tex]6x+4+(14x-4)=180\\6x+4+14x-4=180\\20x=180\\x=\frac{180}{20} \\=9\\\\[/tex]
Substitute x to find m∠13
m∠13= 6x+4 = 6(9)+4 = 36 + 4 = 40°
