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
I got this picture from photomath, hope it helps
8x + 7y = 39
4x - 14y = -68
(multiply each term in second equation by -2)
8x + 7y = 39
-8x + 28y = 136
(add both equations)
35y = 175
(divide both sides by 35)
y = 5
(substitute value of y in one of the equations)
8x + 7(5) = 39
8x + 35 = 39
8x = 4
x = 1/2
(x, y) = (1/2, 5)
3 is the slope, (0,-5) is the y-intercept of the graph.