Question

na proporção x/y = 12/21 sabendo-se x+y =11, calcular o valor de x e y ALGM SABE?

Answer 1

$\frac{x}{y}=\frac{12^{\div(3}}{21^{\div(3}}\\\\\\\frac{x}{y}=\frac{4}{7}$

 POrtanto, $\boxed{x=4}$ e $\boxed{y=7}$!!

Answer 2

x+y=11
x=11-y
$\frac{x}{y} = \frac{12}{21}$
$\frac{11-y}{y}= \frac{12}{21}$
$-21y+231=12y$
$-21y+231-12y=0$
$-33y=-231 .(-1)$
$33y=231$
y=$\frac{231}{33}$
y=$7$
x=11-y
x=$11-7$
x=$4$
x vale 4 e y 7