Question

POR FAVOR
Determine o valor de x em cada uma das seguintes proporções:
c)6/3=x/0,5
d)x+1/5=x/3
e)2/9=x+3/x-1
f) √5/2=x/√20
g)1,2/4,2=2/x
h)3/5x=6/2 1/2
I)2x-3/2=x+1/6
J)x/x-2=x-3/x

Answer 1

Resposta:

c)

$\frac{x}{3} = 2x$

$- 5x = 0$

$x = 0$

d)

$\frac{x + 1}{5} = \frac{x}{3}$

$3(x + 1) = 5x$

$- 2x = - 3$

$x = \frac{3}{2}$

e)

$\frac{2}{9} = \frac{ x+ 3}{x - 1}$

$2(x - 1) = 9(x + 3)$

$2x - 2 = 9 x + 27$

$- 7x = 29$

$x = - \frac{27}{7}$

f)

$\frac{ \sqrt{5} }{2} = \frac{x}{ \sqrt{20} }$

$\frac{ \sqrt{5} }{2} = \frac{x}{ \sqrt{4} \times \sqrt{5} }$

$\frac{ \sqrt{5} }{2} = \frac{x}{2 \sqrt{5} }$

$10 \sqrt{5} = x2 \sqrt{5}$

$x = 5$

g)

$\frac{1.2}{4.2} = \frac{2}{x}$

$\frac{6}{5} \div \frac{21}{5} = \frac{2}{x}$

$\frac{6}{21} = \frac{2}{x}$

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

$x = 7$

h)

$\frac{3}{5x} = \frac{6}{2} \times \frac{1}{2}$

$\frac{3}{5x} = \frac{3}{2}$

$5x = 2$

$x = \frac{2}{5}$

i)

$\frac{2x - 3}{2} = \frac{x + 1}{6}$

$6(2x - 3) = 2(x + 1)$

$12x - 18 = 2x + 2$

$10x = 20$

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

$x = 2$

j)

$\frac{x}{x - 2} = \frac{x - 3}{x}$

${x}^{2} = (x - 2)(x - 3)$

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

$3x - 2x - 6 = 0$

$x - 6 = 0$

$x = 6$