What is the slope of any line perpendicular to the graph of y=-5x+7

The depth of a lake at a certain point, wich is a function of the distance of that point from shore, is 30 feet.

Part a : solve - vp + 40 < 65 for v . part b : solve 7w - 3r = 15 for r show your work!

3-12. write each answer with a reasonable number of figures. find the absolute uncertainty and percent relative uncertainty for each answer. (a) [12.41 (±0.09) + 4.16 (±0.01)] x 7.068 2 (±0.000 4) =? (b) [3.26 (±0.10) x 8.47 (±0.05)] - 0.18 (±0.06) =? (c) 6.843 (±0.008) x 104 + [2.09 (±0.04)- 1.63 (±0.01)] =?