Question

Resolva as equações a)25x²+5x=0 b)64x²+8x=0 c)36x²+6x=0 d)100x²-25x=0 e)18x²-9x=0

Answer 1

Olá...

Resolução:

a)

25x² + 5x = 0

x(25x + 5) = 0

x' = 0

25x + 5 = 0

25x = - 5

x = - 5/25

x" = - 1/5

S= {0; - 1/5}

b)

64x² + 8x = 0

x(64x + 8) = 0

x' = 0

64x + 8 = 0

64x = - 8

x = - 8/64

x" = - 1/8

S= {0; - 1/8

c)

36x² + 6x = 0

x(36x + 6) = 0

x' = 0

36x + 6 = 0

36x = - 6

x = - 6/36

x" = - 1/6

S= {0; - 1/6}

d)

100x² - 25x = 0

x(100x - 25) = 0

x' = 0

100x - 25 = 0

100x = 25

x = 25/100

x" = 1 4

S= {0; 1/4}

e)

18x² - 9x = 0

x(18x - 9) = 0

x' = 0

18x - 9 = 0

18x = 9

x = 9/18

x" = 1/2

S = {0; 1/2}

Bons estudos.

Answer 2

a)

$25 {x}^{2} + 5x = 0 \\ 5x(5x + 1) = 0$

$5x = 0 \\ x = \frac{0}{5} = 0 \\ 5x + 1 = 0 \\ 5x = - 1 \\ x = - \frac{1}{5}$

S={-1/5,0}

b)

$64 {x}^{2} + 8x = 0 \\ 8x(8x + 1) = 0$

$8x = 0 \\ x = \frac{0}{8} = 0 \\8x + 1 = 0 \\ 8x = - 1 \\ x = - \frac{1}{8}$

S={–1/8,0}

c)

$36 {x}^{2} + 6x = 0 \\ 6x(6x + 1) = 0$

$6x = 0 \\ x = \frac{0}{6} = 0 \\ 6x + 1 = 0 \\ 6x = - 1 \\ x = - \frac{1}{6}$

S={–1/6,0}

d)

$100 {x}^{2} - 25x = 0 \\ 25x(4x - 1) = 0$

$25x = 0 \\ x = \frac{0}{25} = 0 \\ 4x - 1 = 0 \\ 4x = 1 \\ x = \frac{1}{4}$

S={¼, 0}

e)

$18 {x}^{2} - 9x = 0 \\ 9x(2x - 1) = 0$

$9x = 0 \\ x = \frac{0}{9} = 0 \\ 2x - 1 = 0 \\ 2x = 1 \\ x = \frac{1}{2}$

S={½, 0}