Question

Na figura as retas r,s e t sao paralelas.Determine o valor de x

Answer 1

$\frac{30}{x+15} = \frac{28}{42}$
$30 . 42 = (x + 15) . 28$
$1260 = 28x + 420$
$1260 - 420 = 28x$
$840 = 28x$
$\frac{840}{28} = x$
$x = 30$