Multiplying a number by 2 and then dividing by 3 is the same as multiplying by what a number

In the xy-plane, if the parabola with equation passes through the point (-1, -1), which of the following must be true?

Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists

Solve the following: 12(x^2–x–1)+13(x^2–x–1)=25(x^2–x–1) 364x–64x=300x