Perpendicular lines have gradients that multiply to give -1
So, the gradient of the line we need is -1/0.2 = -5
If we have the gradient and a point in the line, we can work out the equation using the formula:
y - y1 = m(x - x1)
where m = gradient, y1 = y-coordinate and x1 = x-coordinate of the same point
So, we substitute in our values, and we get:
y - -8 = -5(x - -7)
y+8 = -5x-35
y = -5x-43
Hope I helped! xx
