Since x and y are variables, the sum of 5x and 5y could be literally any number.
x5+y5
1+X+3X+5X+nX+19X+2+nXcan't be solved because it does not equal anything. without an equals sign, numbers can't be moved around. if there was and equals sign, and another equation, it could be solved
is a quintic expression in x (NOT an equation).
2a2+a-6 = (2a-3)(a+2)