1.由题意可知:
(-1/5)x2ym+1为6次项,则2+m+1=6,所以m=3
又知3x2ny5-m与该多项式的次数相同则2n+(5-m)=6,又知m=3,则n=2
2.有题意可知:
3a+2=0.(1)
9a+10b=0.(2)
由(1)可知a=-2/3,将a=-2/3代入(2)中得b=3/5
则3A-5B=3*(-2/3)-5*(3/5)=-5
1.由题意可知:
(-1/5)x2ym+1为6次项,则2+m+1=6,所以m=3
又知3x2ny5-m与该多项式的次数相同则2n+(5-m)=6,又知m=3,则n=2
2.有题意可知:
3a+2=0.(1)
9a+10b=0.(2)
由(1)可知a=-2/3,将a=-2/3代入(2)中得b=3/5
则3A-5B=3*(-2/3)-5*(3/5)=-5