Answer:
Step-by-step explanation:
9y+7=2y+98(being vertically opposite angles)
9y-2y=98-7
7y=91
y=91/7
y=13
x + 3y = 21
Equation of the line: y =mx+ b
Multiply the equation by 3
3y = -x + 21
-31
a - 8x will change to (-7) - 8(3) = -31