0\\ 3x<7\\ x<\frac{7}{3}\\\\ 7-3x=(x+7)^2\\ 7-3x=x^2+14x+49\\ x^2+17x+42=0\\ x^2+3x+14x+42=0\\ x(x+3)+14(x+3)=0\\ (x+14)(x+3)=0\\ x=-3 \vee x=-14\\ " alt="\\\sqrt{7-3x}=x+7\\ 7-3x>0\\ 3x<7\\ x<\frac{7}{3}\\\\ 7-3x=(x+7)^2\\ 7-3x=x^2+14x+49\\ x^2+17x+42=0\\ x^2+3x+14x+42=0\\ x(x+3)+14(x+3)=0\\ (x+14)(x+3)=0\\ x=-3 \vee x=-14\\ " align="absmiddle" class="latex-formula">