Question

-x-y=-20
2x+4y=54
$- \times - y = - 20 \\ 2 \times \ + 4y = 54$
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Answer 1

-x-y=-20

-x=-20+y (*-1)

x=20+y

2(20+y)+4y=54

40+2y+4y=54

6y=54-40

6y=14

y=14/6

y=7/3

-x-7/3=-20 (*-1)

x+7/3=20

x=20-7/3

x= 17,667