What's the difference between 18 and 7

(note i put the graph in so plz )the graph shows the amount of water that remains in a barrel after it begins to leak. the variable x represents the number of days that have passed since the barrel was filled, and y represents the number of gallons of water that remain in the barrel. what is the slope of the line

Find the zeros of the function. write the smaller solution first, and the larger solution second f(x)= (x+6)^2-49

Solve the equation x/4 - 5= -8 -27 -12 -7 12