1)
x²-y²=(x+y)(x-y)
6(x-y)=24
x-y=4
2)
2m²+4mn+2n²-6
=2(m+n)²-6
=2*9-6
=18-6
=12
3)
81^31
=(3^4)^31
=3^124
27^41
=(3^3)^41
=3^123
9^61
=(3^2)^61
=3^122
A>B>C
4)
=[(1+1/2)(1-1/2)]*[(1+1/3)(1-1/3)].*[(1+1/100)(1-1/100)]
=3/2*1/2*4/3*2/3*.*101/100*99/100
=1/2*101/100
=101/200
5)
2^12*5^8
=2^4*2^8*5^8
=2^4*10^8
=16*10^8
10位