x²-5x=x+2 Solve The Following equations by using " completing the square " method. Give your answer correct to four significant figures

Guest Mar 12, 2017

#1**+6 **

x^{2} - 5x = x + 2

Subtract x from both sides.

x^{2} - 6x = 2

Take half of the x coefficient, square it, and add that to both sides.

x^{2} - 6x + 9 = 2 + 9

Now it is a perfect trinomial and you can factor it.

(x - 3)(x - 3) = 11

(x - 3)^{2} = 11

Take the square root of both sides.

x - 3 = ±√(11)

Add 3 to both sides.

x = ±√(11) + 3

x = √(11) + 3 and x = -√(11) + 3

x ≈ 6.3166 and x ≈ -0.3166

hectictar
Mar 12, 2017