Các bạn ơi giúp mik ik nào

TRẮC NGHIỆM

1-A;2-D;3-C;4-B;5-C

TỰ LUẬN

câu 1:

a,4x+16=0

<=>4x=-16

<=>x=-4

b,3x/x+2 -2 =x/x-2

<=>3x(x-2)-2(x-2)(x+2)=x(x+2)

<=>3x^2-6x-2(x^2-4)=x^2+2x

<=>3x^2-6x-2x^2+8-x^2-2x=0

<=>-8x+8=0

<=>-8x=-8

<=>x=1

c,(3x-7)(x+5)=(x+5)(3-2x)

<=>(3x-7)(x+5)-(x+5)(3-2x)=0

<=>(x+5).(3x-7-3+2x)=0

<=>(x+5).(5x-10)=0

<=>x+5=0 hoặc 5x-10 =0

<=>x=-5 hoặc x=2

e,(3x-2).(x^2+1)=(3x-2)

<=>(3x-2).(x^2+1)-(3x-2)=0

<=>(3x-2).(x^2+1-1)=0

<=>x^2.(3x-2)=0

<=>x^2=0 hoặc (3x-2)=0

<=>x=0 hoặc x=2/3

f,108-x/92 + 107-x/93 + 106-x/94 + 105-x/95  + 4=0

<=> (108-x/92 +1)+(107-x/93 +1)+(106-x/94 +1)+(105-x/95 +1)=0

<=>200-x/92 + 200-x/93 + 200-x/94 + 200-x/95=0

<=>(200-x) .(1/92 + 1/93 +1/94 +1/95)=0

vì (1/92 + 1/93 +1/94 +1/95)>0

<=>200-x=0

<=>x=200

g,(x-2).(2x+3)=5(x-2)

<=>(x-2).(2x+3)-5(x-2)=0

<=>(x-2)(2x+3-5)=0

<=>(x-2).(2x-2)=0

<=>x-2=0 hoặc 2x-2=0

<=>x=2 hoặc x=1

h,7x-4=3x+1

<=>7x-4-3x-1=0

<=>4x-5=0

<=>x=5/4

i, 1/x+2 - 1 =5x+7/x+2

<=>1-(x+2)=5x+7

<=>1-x-2-5x-7=0

<=>-8-6x=0

<=>8+6x=0

<=>6x=-8

<=>x=-4/3