Question

Which of the following are solutions to the quadratic equation? Check all that apply. x2+2x-8-0 nB. 28

Answer 1

Solution: Option   

$x^{2}+2x-8=0$

$2^{2}+2\times 2-8=4+4-8=8+8=0$

$\therefore 2$   is a solution

$28^{2}+2\times 28-8\neq$

$\therefore 28$   is not a solution

$1^{2}+2\times 1-8=1+2-8=-5\neq 0$

$\therefore 1$   is not a solution

$\left ( -1 \right )^{2}+2\times \left ( -1 \right )-8=1-2-8=-9\neq 0$

$\therefore -1$   is not a solution

$\left ( -4 \right )^{2}+2\times \left ( -4 \right )-8=16-8-8=0$

$\therefore -4$   is a solution

$4^{2}+2\times 4-8=16$

$\therefore 4$   is not a solution