How do I work out reverse mean

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

Solve -.016x= -16. need solving this

Write an inequality for this description. - one fourth of the opposite of the difference of five and a number is less than twenty.