Question

$\frac{5}{x} = \frac{7}{x + 4}$

Answer 1

$\frac{5}{x} = \frac{7}{x + 4} \\ \\ on \: cross \: multiplying \: we \: get \\ \\ 5(x + 4) = 7x \\ \\ 5x + 20 = 7x \\ \\ 7x - 5x = 20 \\ \\ 2x = 20 \\ \\ x = 10$

Answer 2

Hope this will help you..