Simplify 9^2+4(9^)=21

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)

Sara made $253 for 11 hours of work. at the same rate how much would he make for 7 hours of work?

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters