Question

已知m的2次幂与-2n的2次幂的和为A,1+n的1次幂与-2m的2次幂的差为B,求2A-4B.

Answer 1

已知,m²+(-2n²) = A ,(1+n)-(-2m²) = B ,

可得：2A-4B = 2[m²+(-2n²)]-4[(1+n)-(-2m²)] = 2m²-4n²-4-4n-8m² = -6m²-4n²-4n-4 .