solving using completing the square.

xsquared+4x-10=0

asked by guest
on Nov 24, 2024 at 10:39 am



You asked:

Solve the equation \({x}^{2} + 4 x - 10 = 0\) by completing the square.

MathBot Answer:

The quadratic equation \( {x}^{2} + 4 x - 10 = 0 \) has two solutions: \[ x = -2 + \sqrt{14} , \quad x = -2 - \sqrt{14} \]


The quadratic equation in standard form is: \[ x^{2} + 4 x - 10 = 0 \]

Subtract the constant term \( -10 \) from both sides of the equation: \[ x^{2} + 4 x = 10 \]

Complete the square on the left hand side by adding the square of half the linear coefficient, \( 4 \), to both sides of the equation: \[ x^{2} + 4 x + 4 = 14 \]

Rewrite the left hand side of the equation as a square: \[ \left(x + 2\right)^{2} = 14 \]

Rewrite the right hand side as a square, and subtract from both sides: \[ \left(x + 2\right)^{2} - \left(\sqrt{14}\right)^{2} = 0 \]

Use the identity \( a^2 - b^2 = (a-b)(a+b) \) to rewrite the difference of squared on the left hand side as a product: \[ \left(\left(x + 2\right) - \sqrt{14}\right) \left(\left(x + 2\right) + \sqrt{14}\right) = 0 \]

\[ x = -2 + \sqrt{14} , \quad x = -2 - \sqrt{14} \]