Answer:
[tex](x + 6)^2 = 49[/tex]
[tex]x = 1[/tex] or [tex]x = -13[/tex]
Step-by-step explanation:
Given
[tex]12x = 13 - x^2[/tex]
Using Completing the Square
[tex]12x = 13 - x^2[/tex] ---- Add [tex]x^2[/tex] to both sides
[tex]x^2 + 12x = 13 - x^2 + x^2[/tex]
[tex]x^2 + 12x = 13[/tex]
Divide the coefficient of x by 2; then add the square to both sides
[tex]x^2 + 12x + 6^2 = 13 + 6^2[/tex]
[tex]x^2 + 12x + 36 = 13 + 36[/tex]
[tex]x^2 + 12x + 36 = 49[/tex]
Factorize
[tex]x^2 + 6x + 6x + 36 = 49[/tex]
[tex]x(x + 6) + 6(x + 6) = 49[/tex]
[tex](x + 6)(x + 6) = 49[/tex]
[tex](x + 6)^2 = 49[/tex]
Hence, the equation is [tex](x + 6)^2 = 49[/tex]
Solving further
Take square root of both sides
[tex](x + 6) = \sqrt{49}[/tex]
[tex]x + 6 = \±7[/tex]
[tex]x = \±7- 6[/tex]
This implies that
[tex]x = 7 - 6[/tex] or [tex]x = -7 -6[/tex]
[tex]x = 1[/tex] or [tex]x = -13[/tex]
HEnce, the solutions are [tex]x = 1[/tex] or [tex]x = -13[/tex]
