3=4m+ b
-1=3m+b
m=4
plug in to either equation,
3=16+ b
b=-13
Thus, C would be the answer.
...........................
The perimeter of the equilateral triangle will be 76.2 in
<u>Explanation:</u>
Altitude of an equilateral triangle, H = 22 in
Perimeter, p = ?
Let a be the side of the triangle
We know:

Perimeter = 3a
P = 3 X 25.4 in
P = 76.2 in
Y = 12.1% x 13 + 351
y= 0.012 x 13 + 351
y= 1.573 + 351
y= 352.573 or $352.6