Help i only need help with question 3 but if you could do 4 that would be great

Find the slope of the line that contains the following points. r(-2, 4), s(6, -2)

Aswimming pool had 2.5 million liters of water in it. some water evaporated, and then the pool only had 22 million liters of water in it. what percent of the water evaporated?

Which exponential function has an initial value of 2? f(x) = 2(3x) f(x) = 3(2x)