Bài 1: Tìm x: a) 5.(3-2x)+5.(x-4)=6-4x b) -3.(x-5)+6.(x+2)=9 c) 10.(x-7)-8.(x+5)=6.(-5)+24 d) -7.(3x-5)+2.(7x-14)=28

0 bình luận về “Bài 1: Tìm x: a) 5.(3-2x)+5.(x-4)=6-4x b) -3.(x-5)+6.(x+2)=9 c) 10.(x-7)-8.(x+5)=6.(-5)+24 d) -7.(3x-5)+2.(7x-14)=28”

1. Đáp án:a)x=-11 ; b)x=-6

    

   Giải thích các bước giải:

    a)5. (3-2x)+5. (x-4)=6-4x

   => 15-10x+5x-20=6-4x

   => 15-10x+5x-20-6+4x=0

   => -11-x=0

   => x=-11

   b)=>-3x+15+6x+12=9

   =>3x+27=9

   =>3x=-18

   =>x=-6

   Bình luận

2. a) 5. (3-2x)+5. (x-4)=6-4x

   => 15-10x+5x-20=6-4x

   => 15-10x+5x-20-6+4x=0

   => -11-x=0

   => x=-11

   b)-3.(x-5)+6.(x+2)=9

   => -3x+15+6x+12=9

   => -3x+15+6x+12-9=0

   => 3x+18=0

   => 3x=-18

   => x=-6

   c) 10.(x-7)-8.(x+5)=6.(-5)+24

   =>10x-70-8x-40=-6

   => 10x-70-8x-40+6=0

   => 2x-104=0

   => 2x=104

   => x=52

   d)-7.(3x+5)+2.(7x-14)=28

   => -21x-35+14x-28=28

   => -21x-35+14x-28-28=0

   => -7x-91=0

   => -7x=91

   => x=-13

    

   Bình luận