Номер 821 !!!!!!!!!!!!!!!!!!!

Question

Номер 821 !!!!!!!!!!!!!!!!!!!

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Answer 1

1)4 (7-5x)-(12-20x)=28-20x-12+20x=24
2)2 (3x-y)-(5x-2y)=6x-2y-5x+2y=x
3)6 (x+2y)-3 (2x+y)=6x+12y-6x-3y=9y
4)5 (4x+y)-2 (x-y)=20x+5y-2x+2y=18x+7y