What is the solution to the system of equations x-y=5 and 3x+7y=-5

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.

If f(x) = 4x - 3 and g(x) = x + 4, find (f - g) (x)