Question

preciso da resposta desse sistema de equação por favor

10a + 8b = 5a - 12b - 13
15a - 4b= 16b + 21

5.(x+y)-2.(2x-1) = 1
2.(x+y) - (x-2y) = 3

Answer 1

10a + 8b = 5a - 12b - 13

10a-5a=-8b-12b-13

5a=-20b-13

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15a - 4b= 16b + 21

15a=16b+4b+21

15a=20b+21

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15a+5a=20b+21-20b-13

20a=8

(a=8/20=2/5)

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5a=-20b-13

20b=-5a-13

20b=-5(2/5)-13

20b=-2-13

(b=-15/20=-3/4)

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5.(x+y)-2.(2x-1) = 1

5x+5y-4x+2-1=0

x+5y+1=0

x=-5y-1

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2.(x+y) - (x-2y) = 3

2x+2y-x+2y-3=0

x+4y-3=0

-5y-1+4y-3=0

-y-4=0

-y=4

(y=-4)

x=-5y-1

x=-5(-4)-1

x=20-1

(x=19)