Question

determine X nas proporções a seguir

A)
2 = 1
X +1 5

B)
5 = 2
X-3 8

C)
2=X+1
9 18

C)
5 = 4
X X-1

Obs:
Com a conta do resultado

Answer 1

$\frac{2}{x} = \frac{1}{15} \\ x \times 1 = 2 \times 15 \\ x = 30$
$b) \frac{5}{x} = \frac{2}{ - 38} \\ 2 \times x = 5 \times ( - 38) \\ 2x = - 190 \\ x = \frac{ - 190}{2} \\ x = - 95$
$c) \frac{2}{9} = \frac{x + 1}{18} \\ 9(x + 1) = 2 \times 18 \\ 9x + 9 = 36 \\ 9x = 36 - 9 \\ 9x = 27 \\ x = \frac{27}{9} \\ x = 3$
$d) \frac{5}{x} = \frac{4}{x - 1} \\ 5(x - 1) = 4x \\ 5x - 5 = 4x \\ 5x - 4x = 5 \\ x = 5$