8x + 7y = 19
- 8x
7y = 19 - 8x
÷ 7
y = 2 5/7 - 8/7x
So if that line is perpendicular to the line you're looking for, then the gradient (x value/slope) is the negative reciprocal to the gradient you're looking for, which would then be 7/8. You are told it has a y intercept of -7, so your final answer is:
y = -7/8x - 7
Hope this helps!
