Need help anyone know this as well? Very confusing

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

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28

Elizabeth claims that the fourth root of 2 can be expressed as 2^m since (2^m)^n = 2. find the values of m and n for the case where elizabeth's claim is true.