Text Solve by completing the square: x2+6x−7=0.x^{2}+6x-7=0.x2+6x−7=0. Solution Move the constant to the right and complete: x2+6x=7 ⇒ (x+3)2=7+9=16.x^{2}+6x=7\;\Rightarrow\;(x+3)^{2}=7+9=16.x2+6x=7⇒(x+3)2=7+9=16. x+3=±4 ⇒ x=1 or x=−7.x+3=\pm 4\;\Rightarrow\; x=1\ \text{or}\ x=-7.x+3=±4⇒x=1 or x=−7. x1=1,x2=−7 \boxed{\,x_1=1,\quad x_2=-7\,}x1=1,x2=−7