Question

X²-10X+21=0 ME AJUDEM PVF

Answer 1

a = 1
b = -10
c = 21

delta = b^2 - 4ac
delta = (-10)^2 - 4 × 1 × 21
delta = 100 - 84
delta = 16

x = -b +ou- raiz quadrada de delta / 2a
x = -(-10) +ou- raiz de 16 / 2 × 1
x = 10 +ou- 4 / 2

x' = 10 + 4 / 2 = 14/2 = 7

x'' = 10 - 4 / 2 = 6/2 = 3

Answer 2

$x^2-10x + 21 = 0 \\ \\ a = 1 \\ b = -10 \\ c = 21 \\ \\ x = \frac{-b\pm \sqrt{b^2-4.a.c} }{2.a} \\ \\ x = \frac{-(-10)\pm \sqrt{(-10)^2-4.1.21} }{2.1} \\ \\ x = \frac{10\pm \sqrt{100-84} }{2} \\ \\ x = \frac{10\pm \sqrt{16} }{2} \\ \\ x = \frac{10\pm4}{2} \\ \\ \\ x' = \frac{10+4}{2} \rightarrow x' = \frac{14}{2} \rightarrow x' = 7 \\ \\ x'' = \frac{10-4}{2} \rightarrow x'' = \frac{6}{2} \rightarrow x'' = 3$

Raízes da equação:

$x' = 7 \\ x'' = 3$