Đáp án:
`A=12000` $\\$ `B=10000` $\\$ `C=100` $\\$ `D=0.`
Giải thích các bước giải:
`a)A=a(b+3)-b(3+b)(a=2003,b=1997)`
`A=(b+3)(a-b)`
`A=2000.6`
`A=12000`
`b)B=b^2-8b-c(8-b)(b=108,c=-8)`
`B=b(b-8)+c(b-8)`
`B=(b-8)(b+c)`
`B=100.100=10000`
`c)C=xy(x+y)-2x-2y(x+y=10,xy=12)`
`C=xy(x+y)-2(x+y)`
`C=(x+y)(xy-2)`
`C=10.10=100`
`d)D=x^5(x+2y)-x^3y(x+2y)+x^2y^2(x+2y)(x=10,y=-5)`
`D=(x+2y)(x^5-x^3y+x^2y^2)`
`D=(10-10)(x^5-x^3y+x^2y^2)=0`
