Question

Qual é o valor de x para a = 1, b = -18 e c = 45? *​

Answer 1

$x = \frac{ - b± \sqrt{{b}^{2} - 4 \times a \times c} }{2 \times a} \\ x = \frac{ - ( - 18)± \sqrt{ {( - 18)}^{2} - 4 \times 1 \times 45} }{2 \times 1} \\ x = \frac{18± \sqrt{324 - 180} }{2} \\ x = \frac{18± \sqrt{144} }{2} \\ x = \frac{18±12}{2} \\ x = \frac{18 + 12}{2} = \frac{30}{2} = 15 \\ x = \frac{18 - 12}{2} = \frac{6}{2} = 3$