Question

$\frac{3-x}{4-x} =\frac{5}{7}$
ayuda plz

Answer 1

Respuesta:

$- 7(3 - x) = 5(x - 4) \\ - 21 + 7x = 5(x - 4) \\ - 21 + 7x = 5x - 20 \\ - 21 + 7x - 5x = - 20 \\ - 21 + 2x = - 20 \\ 2x = - 20 + 21 \\ 2x = 1 \\ x = \frac{1}{2}$