ai giúp mình với cần gấp

Đáp án:

`a, 8-(x-15)=2(3-2x)`
`<=> 8-x+15=6-4x`
`<=> 23-x=6-4x`
`<=> -x+4x=6-23`
`<=> 3x=-17`
`<=> x=-17/3`
Vậy `x=-17/3`
`b, -6(1,5-2u)=3(-15+2u)`
`<=> -9+12u=-45+6u`
`<=> 12u-6u=-45+9`
`<=> 6u=-36`
`<=> u=-6`
Vậy `u=-6`
`c, (x+3)^2-x(x+4)=13`
`<=> x^2+6x+9-x^2-4x=13`
`<=> 2x+9=13`
`<=> 2x=13-9`
`<=> 2x=4`
`<=> x=2`
Vậy `x=2`
`d, (y+5)(y-5)-(y-2)^2=-5`
`<=> y^2-25-(y^2-4y+4)=-5`
`<=> y^2-25-y^2+4y-4=-5`
`<=> -29+4y=-5`
`<=> 4y=-5+29`
`<=> 4y=24`
`<=> y=6`
Vậy `y=6`