Question

giúp nốt bài này ạ

Answer 1

1: =>6x^2+21x-2x-7-6x^2+5x-6x+5=7

=>18x-2=7

=>18x=9

=>x=1/2

2: (3x+2)(2x+9)-(x+2)(6x+1)=7

=>6x^2+27x-4x-18-6x^2-x-12x-2=7

=>10x-20=7

=>10x=27

=>x=27/10

3: =>48x^2-12x-20x+5+3x-48x^2-7+112x=81

=>83x=83

=>x=1

4: =>2(6x^2+15x-2x-5)-6(2x^2+4x-x-2)=-6

=>12x^2+26x-10-12x^2-18x+12=-6

=>8x+2=-6

=>8x=-8

=>x=-1

5: =>6x-2x^2-3+x+x^2+x-6=-(x^2-3x+2)

=>-x^2+8x-9+x^2-3x+2=0

=>5x-7=0

=>x=7/5

6: =>2x^2-8x+3x-12+x^2-7x+10=3x^2-12x-5x+20

=>3x^2-12x-2=3x^2-17x+20

=>-12x-2=-17x+20

=>5x=22

=>x=22/5

7: =>24x^2+16x-9x-6-4x^2-16x-7x-28=10x^2-2x+5x-1-33

=>20x^2-16x-34=10x^2+3x-34

=>10x^2-19x=0

=>x(10x-19)=0

=>x=0 hoặc x=19/10