Question

Me ajudem
F(x)= x²- 9x+18​

Answer 1

Resposta:

$x_1=6,\:x_2=3$

Explicação passo-a-passo:

$f(x)= x^2-9x+18\\0= x^2-9x+18\\x^2-9x+18=0\\\\x_{1,\:2}=\frac{-\left(-9\right)\pm \sqrt{\left(-9\right)^2-4\cdot \:1\cdot \:18}}{2\cdot \:1}\\x_{1,\:2}=\frac{-\left(-9\right)\pm \:3}{2\cdot \:1}\\x_1=\frac{-\left(-9\right)+3}{2\cdot \:1},\:x_2=\frac{-\left(-9\right)-3}{2\cdot \:1}$

$x_1=\frac{-\left(-9\right)+3}{2\cdot \:1}\\=\frac{9+3}{2\cdot \:1}=\frac{12}{2\cdot \:1}\\=\frac{12}{2}\\=6\\\\x_2=\frac{-\left(-9\right)-3}{2\cdot \:1}\\=\frac{9-3}{2\cdot \:1}\\=\frac{6}{2\cdot \:1}\\=\frac{6}{2}\\=3\\\\x_1=6,\:x_2=3$