Question

resolva a equação x2-11x+18:0

Answer 1

x² - 11x + 18 = 0
Δ= - 11² - 4 . 1 . 18
Δ= 49
x' = - (-11) + 7 / 2 = 18 / 2 = 9
x" = -(-11) - 7 / 2 = 4/2= 2

Answer 2

Explicação passo-a-passo:

$\sf x^2-11x+18=0$

$\sf \Delta=(-11)^2-4\cdot1\cdot18$

$\sf \Delta=121-72$

$\sf \Delta=49$

$\sf x=\dfrac{-(-11)\pm\sqrt{49}}{2\cdot1}=\dfrac{11\pm7}{2}$

$\sf x'=\dfrac{11+7}{2}~\Rightarrow~x'=\dfrac{18}{2}~\Rightarrow~\red{x'=9}$

$\sf x"=\dfrac{11-7}{2}~\Rightarrow~x"=\dfrac{4}{2}~\Rightarrow~\red{x"=2}$