Question

qual desses numero e raiz da equação x2-11x+18=0

Answer 1

Olá;!

Resolução!!

x² - 11x + 18 = 0

a = 1, b = - 11, c = 18

∆ = b² - 4ac
∆ = ( - 11 )² - 4 • 1 • 18
∆ = 121 - 72
∆ = 49

x = - b ± √∆ / 2a
x = - ( - 11 ) ± √49 / 2 • 1
x = 11 ± 7 / 2
x' = 11 + 7 / 2 = 18/2 = 9
x" = 11 - 7 / 2 = 4/2 = 2

S = { 2, 9 }

Espero ter ajudado;;

Answer 2

Explicação passo-a-passo:

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

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

$\sf \Delta=121-72$

$\sf \Delta=49$

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

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

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