Question

por favor alguem me ajuda
A) x²-1=0
B) x²-81=0
C) x²-10x=0
D) 9x²-4=0
E) x²-7x=0
POR FAVOR ALGUEM ME AJUDA

Answer 1

Explicação passo-a-passo:

a)

${x}^{2} - 1 = 0 \\ delta = {b}^{2} - 4ac \\ delta = 0 - 4.1.( - 1) \\ delta = 4 \\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{0 + 2}{2} = 1 \\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{0 - 2}{2} = - 1$

S = { 1, -1 }

b)

${x}^{2} - 81 = 0 \\ delta = {b}^{2} - 4ac \\ delta = 0 - 4.1.( - 81) \\ delta =32 4 \\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{0 + 18}{2} = 9 \\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{0 - 18}{2} = - 9$

S = { -9, 9 }

c)

${x}^{2} - 10x = 0 \\ delta = {b}^{2} - 4ac \\ delta = 100 - 4.1.0\\ delta = 100 \\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{10+ 10}{2} = 1 0\\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{10 - 10}{2} = 0$

S = { 0, 10 }

d)

$9 {x}^{2} - 4 = 0 \\ delta = {b}^{2} - 4ac \\ delta = 0 - 4.9.( - 4) \\ delta = 144 \\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{0 + 12}{18} = \frac{2}{3} \\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{0 - 12}{18} = - \frac{2}{3}$

S = { -2/3, 2/3 }

e)

${x}^{2} - 7x = 0 \\ delta = {b}^{2} - 4ac \\ delta = 49 - 4.1.0 \\ delta = 4 9\\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{7+ 7}{2} = 14 \\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{7 - 7}{2} = 0$

S = { 0, 7 }

Espero ter ajudado!

Answer 2

\begin{gathered}{x}^{2} - 1 = 0 \\ delta = {b}^{2} - 4ac \\ delta = 0 - 4.1.( - 1) \\ delta = 4 \\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{0 + 2}{2} = 1 \\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{0 - 2}{2} = - 1\end{gathered}x2−1=0delta=b2−4acdelta=0−4.1.(−1)delta=4x=2a−b+deltax=20+2=1x=2a−b−delta=20−2=−1

S = { 1, -1 }

b)

\begin{gathered}{x}^{2} - 81 = 0 \\ delta = {b}^{2} - 4ac \\ delta = 0 - 4.1.( - 81) \\ delta =32 4 \\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{0 + 18}{2} = 9 \\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{0 - 18}{2} = - 9\end{gathered}x2−81=0delta=b2−4acdelta=0−4.1.(−81)delta=324x=2a−b+deltax=20+18=9x=2a−b−delta=20−18=−9

S = { -9, 9 }

c)

\begin{gathered}{x}^{2} - 10x = 0 \\ delta = {b}^{2} - 4ac \\ delta = 100 - 4.1.0\\ delta = 100 \\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{10+ 10}{2} = 1 0\\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{10 - 10}{2} = 0\end{gathered}x2−10x=0delta=b2−4acdelta=100−4.1.0delta=100x=2a−b+deltax=210+10=10x=2a−b−delta=210−10=0

S = { 0, 10 }

d)

\begin{gathered}9 {x}^{2} - 4 = 0 \\ delta = {b}^{2} - 4ac \\ delta = 0 - 4.9.( - 4) \\ delta = 144 \\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{0 + 12}{18} = \frac{2}{3} \\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{0 - 12}{18} = - \frac{2}{3}\end{gathered}9x2−4=0delta=b2−4acdelta=0−4.9.(−4)delta=144x=2a−b+deltax=180+12=32x=2a−b−delta=180−12=−32

S = { -2/3, 2/3 }

e)

\begin{gathered}{x}^{2} - 7x = 0 \\ delta = {b}^{2} - 4ac \\ delta = 49 - 4.1.0 \\ delta = 4 9\\ \\ x = \frac{ - b + \sqrt{delta} }{2a} \\ x = \frac{7+ 7}{2} = 14 \\ \\ x = \frac{ - b - \sqrt{delta} }{2a} = \frac{7 - 7}{2} = 0\end{gathered}x2−7x=0delta=b2−4acdelta=49−4.1.0delta=49x=2a−b+deltax=27+7=14x=2a−b−delta

mais ou menos isto ai fals gesiga