Question

determine whether x =-2 is a solution of the quadratic equation x^2-2x+8=0 or not

Answer 1

Putting the value of x in quadratic equation x²-2x+8=0
(-2)²-2(-2)+8=0
4+4+8=0
16 is not equal to 0 that's why the value of x is not a solution of that quadratic equation.
Hope it is correct.

Answer 2

${x}^{2} - 2x + 8 = 0 \\ for \: x = - 2 \\ ({ - 2})^{2} - 2( - 2) + 8 = 0 \\ 4 + 4 + 8 = 0 \\ LHS is not equal to RHS \\ x = - 2 \: is \: not \: a \: solution$