The second equation is y=5x+2
Divide by the coefficient of y.
y = (45/9)x
y = 5x
The constant of proportionality is 5.
30
(-3)*(-2)=6
6*5=30
Double negatives makes a positive
Since in y=8, the slope is 0 (because there is no x) and b is 8 in y=mx+b, we know that the perpendicular line is x=(something) because the perpendicular lines of y=<number> are x=<number> due to that y=<number> equations are strictly horizontal while x=<number> equations are strictly vertical. Since we know that x=<number> has to pass through (7, 8), x =7
[70.70 x 10 ]/100 = 7.70
Answer is 7.70$