An integer by -3 is 21 what is the integer? Can someone help me with this and show the work for it

Four equations are shown below.equation 1: y=2*equation 2: y=2x-5equation 3: y=x2 + 6equation 4: tdentify one linear equation and one nonlinear equation from the list.why each equation you identified is linear or nonlinear.nd one nonlinear equation from the list. state a reasonlinear equation