Answer:
3x+y=-31
Step-by-step explanation:

Slope of perpendicular line is -3.

Sub in the point (10, -1)

Step-by-step explanation:
x = -12
y = x/2 + 9
y = -12/2 + 9
y = -6 + 9
y = 3
25/5 = 5
and also
15/3 = 5
so
(3x+ 8)/5 = 4
3x + 8 = 20
3x = 12
x = 12/3
x = 4
answer is x = 4
Answer=C 2 1/2
(12 1/2)÷5=2 1/2
or
12.5/5=2.5=2 1/2