Question

determine o valor de x
a) x/4=7/14
b) 2x/4=7/14
c) 3/4=8/x+1
d)3/4x=8/x-1

alguem ai ajuda?​

Answer 1

Resposta:

A)

$\frac{ x }{ 4 } = \frac{ 7 }{ 14 }$

$7x=2\times 7$

$7x = 14$

$x = \frac{14}{7}$

$x = 2$

B)

$\frac{ 2x }{ 4 } = \frac{ 7 }{ 14 }$

$7\times 2x=2\times 7$

$14x = 14$

$x = \frac{14}{14} \\ x = 1$

C)

$\frac{ 3 }{ 4 } = \frac{ 8 }{ x+1 } \\ 3\left(x+1\right)=4\times 8 \\ 3x+3=4\times 8 \\ 3x+3=32 \\ 3x = 32 - 3 \\ 3x=29 \\ x=\frac{29}{3} \\ x = \frac{29}{3} = 9\frac{2}{3} \approx 9.666666667$

D)

$\frac{ 3 }{ 4x } = \frac{ 8 }{ x-1 } \\ \left(x-1\right)\times 3=4x\times 8 \\ 3x-3=4x\times 8 \\ 3x-3=32x \\ 3x-3-32x=0 \\ -29x-3=0 \\ -29x=3 \\ x=\frac{3}{-29} \\ x=-\frac{3}{29}\approx -0.103448276$