How do you solve using the completing the square method $7x²+9x+1=0$ ?

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Answer 1 · 2018-03-03T07:04:49

$color(green)(x = -1.5429, -2.9571$

$7x^2 + 9x + 1 = 0$

$cancel7(x^2 + (9/7)x + (1/7)) = 0$

$(x^2 + (2 * (9/14) x) = -(1/7)$

Add $(9/14)^2$ to both sides.

$x^2 + (2 * (9/14) x) + (9/14)^2 = -1/7 + 9 / 14 = 1/2$

$(x+ 9/14))^2 = (sqrt (1/2))^2$

$x + (9/4) = +- sqrt (1/2)$

$x = +sqrt(1/2) - (9/4), -sqrt(1/2) - (9/4)$

$color(green)(x = -1.5429, -2.9571$

How do you solve using the completing the square method 7x²+9x+1=0 7x²+9x+1=0 ?