Question

b) x+2y=17 2x-2y=-2
c) 3x+5y=11 2x -y=16​

Answer 1

b) {x + 2y = 17

{2x - 2y = - 2

3x = 15

x = 15

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3

x = 5

x + 2y = 17

5 + 2y = 17

2y = 17 - 5

2y = 12

y = 12

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2

y = 6

S = {(5 , 6)}

c) {3x + 5y = 11

{2x - y = 16

2x - y = 16 . (5)

10x - 5y = 80

{3x + 5y = 11

{10x - 5y = 80

13x = 91

x = 91

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13

x = 7

3x + 5y = 11

3 . 7 + 5y = 11

21 + 5y = 11

5y = 11 - 21

5y = - 10

y = - 10

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5

y = - 2

S = {(7 , -2)}