两道preps数学

西风瘦马

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这种题错了好几次， 想问NN有没有办法在不用算出的情况下就能看出实际只有一个方程，多谢

graysytl

1) only when n=2 and n=4, 2^n=n^2 ,so the answer is 2

2) Both two conditions give us 2A=B

but we don't know what is A+B and what is the intersts rate of each investment? so we don't know the amount of "dollors"  she spend on either investments.