Question

（1）如果2x+y=4,xy=3,那么2乘以x的2次方乘以y+x乘以y的2次方=_______

Answer 1

(1)2(x^2)y+xy^2=xy(2x+y)=3*4=12.(2)∵m^2=n+2,n^2=m+2∴m^2-n^2=(n+2)-(m+2)=n-m=-(m-n)∵m^2-n^2=(m+n)(m-n)∴(m+n)(m-n)=-(m-n)∵m≠n∴m-n≠0∴m+n=-1∴(m+n)^3=(-1)^3=-1.(3)∵2^80-1=(2^40+1)(2^40-1)=(2^40+...