1) 2(x-5)-3(x+7)=14 2) 7(x-9)-5(6-x)= -6 +11 3) 7x -4 =20+3x 4) x+15=20 – 4x Giải giúp mik vs ạ !! Cảm ơn

1 bình luận về “1) 2(x-5)-3(x+7)=14 2) 7(x-9)-5(6-x)= -6 +11 3) 7x -4 =20+3x 4) x+15=20 – 4x Giải giúp mik vs ạ !! Cảm ơn”

1. 1)2(x-5)-3(x+7)=14

   ⇒2x-10-3x-21=14

   ⇒2x-3x=14+10+21

   ⇒-x=45

   ⇒x=-45

   2)7(x-9)-5(6-x)=-6+11

   ⇒7x-63-30+5x=5

   ⇒7x+5x=5+30+63

   ⇒12x=98

   ⇒x=\frac{49}{6}

   3)7x-4=20+3x

   ⇒7x-3x=20+4

   ⇒4x=24

   x=6

   4)x+15=20-4x

   ⇒x+4x=20-15

   ⇒5x=5

   ⇒x=1

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