(1)2分之1* x^2+2x+2= (2)x^3-4x²y +4xy²= (3)已知2a-3b=6,ab=7,则代数式4a³b-12a²b²+9ab³ (4)若(x+1)
问题描述:
(1)2分之1* x^2+2x+2= (2)x^3-4x²y +4xy²= (3)已知2a-3b=6,ab=7,则代数式4a³b-12a²b²+9ab³ (4)若(x+1)²+(y-2)²=0,则x²+y²= (5) 若a²b²-4a+2b+5=0,则ab=
答
1)2分之1* x^2+2x+2= 1/2(x²+4x+4)=1/2(x+2)²(2)x^3-4x²y +4xy²= x(x²-4xy+4y²)=x(x-2y)²(3)已知2a-3b=6,ab=7,则代数式4a³b-12a²b²+9ab³ =ab(4a²-12...