Помогите номер 2 и 4

Question

Помогите номер 2 и 4

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Comments

1)-1/20

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2)x+2x+x+18=108

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4x=90

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x=22.5

Answer 1

21х=-52÷15 +29÷12
21х=(-208+145)÷60
21х=-63÷60
21х=-21÷20
х=-1÷20