Which expression is equivalent to 1/3 (6m+15) +3

Which representation has a constant of variation of -2.5

Ateam of runners is needed to run a 1 2 -mile relay race. if each runner must run 1 4 mile, how many runners will be needed?

What are the solutions for the following system? -2x^2+y=-5 y=-3x^2+5