Resposta :
[tex]\Delta =b^{2} -4ac=( -7)^{2} -4\cdotp 1\cdotp 6=25 \\ \\ x=\frac{-b\pm \sqrt{\Delta }}{2a} =\frac{7\pm 5}{2\cdotp 1} \Longrightarrow \boxed{x=6\lor x=1} \\ \\ \therefore \boxed{\boxed{S=\{x\in \mathbb{R} |x=1\lor x=6\}}}[/tex]
[tex]\Delta =b^{2} -4ac=( -7)^{2} -4\cdotp 1\cdotp 6=25 \\ \\ x=\frac{-b\pm \sqrt{\Delta }}{2a} =\frac{7\pm 5}{2\cdotp 1} \Longrightarrow \boxed{x=6\lor x=1} \\ \\ \therefore \boxed{\boxed{S=\{x\in \mathbb{R} |x=1\lor x=6\}}}[/tex]