Answer
6 and 7 are the solutions of the quadratic equation $x^2-13x+42=0$.
Work Step by Step
RECALL:
If $(x-a)(x-b)=0$, then $x=a$ and $x=b$ are solutions of the equation $(x-a)(x-b)=0$.
Since 6 and 7 are solutions of the quadratic equation, then the equation must be:
$(x-6)(x-7)=0$
Multiply the binomials to have:
$\\x(x-7) -6(x-7)=0
\\x^2-7x-6x-6(-7)=0
\\x^2-13x+42=0$
