How do you solve using the completing the square method $x^{2} + 2 x = 3$ $x^2 + 2x = 3$ ?

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Answer 1 · 2018-04-09T13:09:36

$x = 1$ $x=1$

Adding 1 on both sides
= $x^{2} + 2 x + 1 = 3 + 1$ $x^2+2x+1=3+1$

= ${(x + 1)}^{2} = 4$ $(x+1)^2=4$

Taking square root on both sides

= $\sqrt{{(x + 1)}^{2}} = \sqrt{4}$ $sqrt((x+1)^2)=sqrt4$

= $x + 1 = \pm 2$ $x+1=+-2$

= $x = 1$ $x=1$ & $x = - 3$ $x=-3$

Check

= ${(1)}^{2} + 2 (1) = 3$ $(1)^2+2(1)=3$

= $3 = 3$ $3=3$

Also ${(- 3)}^{2} + 2 (- 3) = 3$ $(-3)^2+2(-3)=3$

= $3 = 3$ $3=3$

Hope it helps!

How do you solve using the completing the square method x^2 + 2x = 3 x2+2x=3x^2 + 2x = 3 ?