Question

qual o valor de x na proporcao (x-3)/x=4/5 ?

Answer 1

vamos lá...

$\frac{x-3}{x} = \frac{4}{5} \\ \\ 5(x-3)=4x \\ \\ 5x-15=4x \\ \\ 5x-4x=15 \\ \\ x=15$

Answer 2

( x - 3)/ x = 4/5
multiplicar em cruz
5 ( x - 3) = 4 . x
5x - 15 = 4x
5x - 4x = 15
x = 15 ****