HELp show work too pleaseee

If square root x = -7, then x= -49 true or false

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

Need showing work for this problem 56.25 ×25.80