Ineed this done soon! estimate the volume of the football. compare the football to the table tennis balls by dragging the football over the table tennis balls to asses the size

John used linear combination to solve the system of equations shown. he did so by multiplying the first equation by -3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by? 4x-6y=23x+5y=11