Question

tìm x  : 4 I 8x - 3 I + 5 I 3 - 2x I = 18

Answer 1

`4|8x-3|+5|3-2x|=18`

`<=>4|8x-3|+5|2x-3|=18`

Nếu `x>=3/2=>|8x-3|=8x-3,|2x-3|=2x-3`

`pt<=>4(8x-3)+5(2x-3)=18`

`<=>32x-12+10x-15=18`

`<=>42x=27+18=45`

`<=>x=45/42(l)`

Nếu `x<=3/8=>|8x-3|=3-8x,|2x-3|=3-2x`

`pt<=>4(3-8x)+5(3-2x)=18`

`<=>12-32x+15-10x=18`

`<=>27-42x=18`

`<=>9=42x`

`<=>x=3/14(tm)`

Nếu `3/9<=x<=3/2=>|8x-3|=8x-3,|2x-3|=3-2x`

`pt<=>4(8x-3)+5(3-2x)=18`

`<=>32x-12+15-10x=18`

`<=>22x+3=18`

`<=>22x=15`

`<=>x=15/22(tm)`

Vậy x=15/22 hoặc x=3/14