Question

Preciso muito de ajuda ...?.?.?.

Answer 1

Ola Rafaela
d)

-x - y = 1
2x + 2y = 4

x + y = -1
x + y = 2

sistema impossivel

e) 

1/x + 1/y = 5/xy

(x - y)/x  + 1 = 4/3

(x - y)/x = 4/3 - 3/3 = 1/3

3x - 3y = x
2x = 3y
y = 2x/3

1/x + 3/2x = 15/2x²

1 + 3/2 = 15/2x

5/2 = 15/2x

5 = 15/x

x = 15/5 = 3

y = 2x/3 = 2*3/3 = 2


f)

x/2 = y/3

2/(x + y) = 1/5

3x - 2y = 0
x + y = 10
2x + 2y = 20
5x = 20
x = 20/5 = 4
y = 10 - x = 10 - 4 = 6

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