Question

calcule o valor de x e y, sabendo que:

a)
x+y=72
x/3=y/6

b)
x+y=35
x/5=y/2

Answer 1

a)

{x + y = 72
{x/3 = y/6

x + y = 72
x = 72 - y
x = 72 - 48
x = 24

x/3 = y/6
72 - y/3 = y/6
6 * (72 - y) = 3y
432 - 6y = 3y
-6y-3y = -432
-9y = -432 .(-1)
9y = 432
y = 48



b) 

{x + y = 35
{x/5 = y/2


x + y = 35
x = 35 - y
x = 35 - 10
x = 25

35-y/5 = y/2 
 2 * (35 - y) = 5 * y
 70 - 2y = 5y
 -2y-5y = -70
 -7y = -70 .(-1)
 7y = 70
 y = 10 

Answer 2

A) x=72-y
72-y=y/6
72-y=3y/6
72-y=y/2
(72-y).2=y
144-2y=y
3y=144
y=48
X=72-48=24

B) x=35-y
35-y=5y/2
(35-y).2=5y
70-2y=5y
7y=70
y=10
x=35-10=25