If a height of a cone is doubled then keeping the same radius how much time the volume will increase

Find the slope and the y-intercept if there's one and the equation of the line given these two points( 3, 2) and( 3, -4)

Suppose your school costs for this term were $4900 and financial aid covered 3/4 of that amount. how much did financial aid cover? and how much do you still have to pay?

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2