Question

Calcule o valor real de x em:

a) x/3 = 3/2
b) 4x/5 = x+1/3
c) 2-x/x+5 = 3/4
d) x-1/x-2 = 3/2


( barra "/" = a sobre)
(cálculos pfv)

Answer 1

Vamos lá!

a) Resposta:
$\frac{x}{3} = \frac{3}{2} \\ \\ 2x = 9 \\ x = \frac{9}{2}$

b) Resposta:
$\frac{4x}{5} = \frac{x+1}{3} \\ \\ 4x.3= 5.(x + 1) \\ 12x = 5x + 5 \\ 12x - 5x = 5 \\ 7x = 5 \\ x = \frac{5}{7}$

c) Resposta: 
$\frac{2-x}{x+5} = \frac{3}{4} \\ \\ 4.(2-x)= 3.(x+5) \\ 8 - 4x = 3x + 15 \\ 3x + 4x = 8 -15 \\ 7x = -7 \\ \\ x = -\frac{7}{7} \\ \\ x = -1$

d) Resposta:
$\frac{x-1}{x-2} = \frac{3}{2} \\ \\ 2.(x-1) = 3.(x-2) \\ 2x-2=3x-6 \\ 3x - 2x = 6 -2 \\ x = 4$

Feito! ;)