Respostas

2013-12-06T08:24:02-02:00
X+y = 20 --> y = 20-x
2x = 3y
x²-y² = ...

2x = 3.(20-x)
2x = 60-3x
2x+3x = 60
5x = 60
x = 60/5
x = 12

y = 20-x
y = 20-12
y = 8

12² - 8² = 144 - 64 = 80
1 4 1
2013-12-06T08:50:51-02:00


x + y = 20  

2x= 3y

(x -Y)²


x + y = 20        x = 20 - y


2x = 3y

2. (20 - y) = 3y

40 - 2y = 3y

-2y -3y = - 40

-5y = -40

y = 8


x + y = 20

x + 8 = 20

x = 20 - 8

x = 12


(x - y)² =

(12 - 8)² =

(4)² = 16



1 4 1