Question

caucule o valor de x nas proporsoes

a) x-3/4= x/5

b)x+3/x-2=3/2

c) x-2/12 =5/20

Answer 1

Explicação passo-a-passo:

$a) \frac{x - 3}{4} = \frac{x}{5} \\ 5(x - 3) = 4 \times x \\ 5x - 15 = 4x \\ 5x + 4x = 15 \\ 9x = 15 \\ x = \frac{15}{9} \\ x = \frac{5}{3}$

$b) \frac{x + 3}{x - 2} = \frac{3}{2} \\ 2(x + 3) = 3(x - 2) \\ 2x + 6 = 3x - 6 \\ 2x - 3x = - 6 - 6 \\ - x = - 12 \\ x = 12$

$\frac{x - 2}{12} = \frac{5}{20} \\ 20(x - 2) = 12 \times 5 \\ 20x - 40 = 60 \\ 20x = 60 + 40 \\ 20x = 100 \\ x = \frac{100}{20} \\ x = 5$