Question

URGENTE
Resolva os sistemas abaixo.
a)
î
í
ì
- =
+ =
8
2 7
x y
x y
b)
î ( ) í
ì
× + =
- =
3 27
5
x y
x y
c)
î
í
ì
+ = -
- =
5 2
2 7
x y
x y
d)
î
í
ì
+ - + =
= +
a b a​

Answer 1

Resposta:

Resposta:

a) 2x + y = 7 2 × 5 + y = 7

x - y = 8 10 + y = 7 S = (5, -3)

3x = 15 y = 7 - 10

x = 15/3 y = -3

x = 5

b) x - y = 5 x - y = 5 7 + y = 9

3 × (x + y) = 27 x + y = 9 y = 9 - 7

x - y = 5 2x = 14 y = 2 S = (7,2)

3x + 3y = 27(:3) x = 14/2

x = 7

c) 2x - y = 7 x + 5 × 1 = -2

x + 5y = -2 x + 5 = -2

2x - 4 = 7 x = -2 - 5 S = (-7, 1)

-2x - 10 y = 4 x = -7

-11y = 11(-1)

11y = -11

y = -11/11

y = 1

d)3a = 16 + b -9a+3b = -48 3 × 11/2 - b 2(a + 1) - 3(b + 2) =a a - 3b = 4 33/2 - b =16

3a - b =16 -8a = -44(-1) 33-2b/2=32/2

2a + 2 - 3b - 6-a=0 8a = 44 -2b = 32 - 33

3a - b = 16 a = 44/8 ÷ 4 -2b = -1

a - 3b - 4 = 0 a = 11/2 2b = 1

3a - b = 16(-3) b = 1/2

a - 3b = 4

S = (11/2, 1/2)