Consider the quadratic equation y^2-y=6. What is the error with the solution below?

I can not see any "solution below", I can offer you the solutions of the equation you gave

y^2-y-6=0 = > y^2-3y+2y-6=0 = > y (y-3) + 2 (y-3) = 0 = > (y-3) (y+2) = 0

y-3=0 or y+2=0 = > y=3 or y = - 2

Check 1: 3^2 - 3 = 6 = > 9-3=6 = > 6=6 Identity prove solution

Check 2: (-2) ^2 - (-2) = 6 = > 4+2=6 = > 6=6 Identity prove solution

Good luck!