Question

me ajude reponder os esses exercicios da foto

Answer 1

Resposta:

a) $x=3$

b) $x = 3$

c) $x=10$

d) $x=2$

Explicação passo-a-passo:

a) $\frac{x+1}{4} = \frac{5}{5}$

$\frac{x +1}{4} = 1$

$x+1 = 4$

$x = 4-1$

$x=3$

b) $\frac{5}{2x-1} = \frac{4}{x+1}$

$5\times(x+1) = (2x-1)\times 4$

$5x + 5 = 8x - 4$

$5+4 = 8x - 5x$

$9 = 3x$

$\frac{9}{3} = x$

$x = 3$

c) $\frac{3x}{x-1} = \frac{4x}{x+2}$

$3x\times (x+2) = 4x\times(x-1)$

$3x^{2} + 6x = 4x^{2} -4x$

$6x +4x = 4x^{2} -3x^{2}$

$10x = x^{2}$

$x^{2} -10x = 0$

$x\times(x-10) = 0$

entao:

$x=0$                      ou                    $x-10 =0$

                                                     $x=10$

d) $\frac{4}{x} = \frac{2}{3x-5}$

$2x = 4\times(3x-5)$

$2x = 12x - 20$

$20 = 12x -2x$

$20=10x$

$\frac{20}{10} = x$

$x=2$