1.2a-1=0,3+b=0.a=1/2,b=-3.(a-b)²=(1/2+3)²=49/4,a+b²=1/2+(-3)²=19/2.
2.(3m²-2m)-2(m²-3/2m)+1=3m²-2m-2m²+3m+1=m²+m+1=0.
3.A+6B=2y²+2ky-2y-1+6(-y²+y-1)=2y²+2ky-2y-1-6y²+6y-6=-4y²+(2k+4)y-7
A+6B的值与y无关,所以,2k+4=0,k=-2.
1.2a-1=0,3+b=0.a=1/2,b=-3.(a-b)²=(1/2+3)²=49/4,a+b²=1/2+(-3)²=19/2.
2.(3m²-2m)-2(m²-3/2m)+1=3m²-2m-2m²+3m+1=m²+m+1=0.
3.A+6B=2y²+2ky-2y-1+6(-y²+y-1)=2y²+2ky-2y-1-6y²+6y-6=-4y²+(2k+4)y-7
A+6B的值与y无关,所以,2k+4=0,k=-2.