Find the roots (if they exist) by completing the square: `2x^2+x+4=0`

Find the roots (if they exist) by completing the square: 2x^2-7x+3=0

Find the roots (if they exist) by completing the square: 3x^2+11 x+10=0

Find the roots (if they exist) by completing the square: x^2-4a x+4a^2-b^2=0

Find the roots (if they exist) by completing the square: sqrt(2)x^2-3x-2sqrt(2)=0

Find the roots (if they exist) by completing the square: x^2-4sqrt(2)x+6=0

Find the roots (if they exist) by completing the square: x^2-(sqrt(2)+1)x+sqrt(2)=0

Find the roots of the following quadratic equations, if they exist, by the method of completing the square: 2x^2 +x-4=0

Find the roots of the quadratic equations (if they exist) by the method of completing the square. 4x^2+4sqrt(3)x+3=0

Find the roots of 4x^2+3x+5=0 by the method of completing the square.

Solve 4x^(2)-8x-3=0 by completing the square.