Answer:
Step-by-step explanation:
Angles 1 and 3 are same as vertical pair, they are also same with angles 5 and 7 for same reason.
<u>Angle 8 is supplementary with angle 5, so:</u>
m∠1 = m∠3 = m∠5 = 180° - 64° = 116°
Idk what linear combination is but you can solve this way:
3x+y=4
-2x-y=-5
x=-1
3(-1)+y=4
-3+y=4
y=7
So x=-1 and y=7