Question

AJUDEEM!!!! PELO AMOR DE DEUS!!!

1- Calcule o valor das incógnitas a cada item:

a) x\4 = y\6 e x + y = 15

b) 2x\8 = y\6 e 2x - y = 3 

c) x\y = 9\6 e x + y = 35

Answer 1

a) $\frac{x}{4} =\frac{y}{6} \\ 6x=4y$
$x+y=15 \\ x=15-y$
$6*(15-y)=4y\\90-6y=4y\\10y=90\\y=9$
$x=15-9=6$

b)$12x=8y \\ y=2x-3$
$12x=16x-24\\4x=24\\x=6$
$y=12-3=9$
c)$6x=9y \\ x=35-y$
$6*(35-y)=9y\\210-6y=9y\\210=15y\\y=14$
$x=35-14=21$