A cliff diver dives from a ledge that is 90 feet above the surface of water. The diver reaches a depth of 60 feet under the surface of the water before returning to the surface. What was the driver's change in elevation from the highest point to the lowest point?

i do not get it

Step-by-step explanation:

the answer is 510

step-by-step explanation:

15 • 13 = 195

15 • 12 = 180

15 • 5 = 75

12 • 5 = 60

195 + 180 = 375

375 + 75 = 450

450 + 60 = 510

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graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.