Question

a) X+y = 12 X-y = -4 b) X+y=6 X-y= -2 c) 2x+y=5 3x_4y=13 d) 2x-3y = -4 5x+y=7 help 4 questão

Answer 1

Resposta:

Explicação passo-a-passo:

Sistemas com 2 incógnitas

A)

X+y = 12

X-y = -4 (+)

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2x = 8

x = 8/2

x = 4

x + y = 12

4 + y = 12

y = 12 - 4

y = 8

_____________

b)

X+y=6

X-y= -2 (+)

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2x = 4

x = 4/2

x = 2

x + y = 6

2 + y = 6

y = 6 - 2

y = 4

___________

c)

2x+y=5 (4)

3x-4y=13

8x + 4y = 20

3x - 4y = 13 (+)

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11x = 33

X = 33/11

X = 3

2x + y = 5

2.3 + y = 5

6 + y = 5

y = 5-6

y = - 1

_____________

d)

2x-3y = -4

5x+y=7 (3)

2x - 3y = - 4

15x + 3y = 21 (+)

17x = 17

x = 17/17

x= 1

5x + y = 7

5.1 + y = 7

5 + y = 7

y = 7 - 5

Y = 2