Question

What is the solution set?

Answer 1

$\left \{ {{y=x^2+2x+7} \atop {y=x+7}} \right. \left \{ {{x+7=x^2+2x+7} \atop {y=x+7}} \right. \left \{ {{x^2+2x-x+7-7=0} \atop {y=x+7}} \right. \left \{ {{x^2+x=0} \atop {y=x+7}} \right. \\\left \{ {{x(x+1)=0} \atop {y=x+7}} \right. \left \{ {{x_1=0, x_2=-1} \atop {y_1=0+7},y_2=-1+7} \right. \left \{ {{x_1=0, x_2=-1} \atop {y_1=7},y_2=6} \right.$

There are 2 solution sets: (0,7) and (-1;6).