1:2(a+b)(-a+b)-3(2a-b)(-b-2a) 答案是10a的平方-b的平方.2:(2+1)(2的平方+1)(2的4次方+1)(2的8次方+1)……(2的2n次方+1) 答案是2的4n次方-1.快.

(1).2(a+b)(-a+b)-3(2a-b)(-b-2a)
=2(b^2-a^2)-3(b^2-4a^2)
=2b^2-2a^2-3b^2+12a^2
=10a^2-b^2
(2).(2+1)(2^2+1)(2^4+1)(2^8+1).(2^(2n)+1)
=(2-1)(2+1)(2^2+1)(2^4+1)(2^8+1).(2^(2n)+1)
=(2^2-1)(2^2+1)(2^4+1)(2^8+1).(2^(2n)+1)
=(2^4-1)(2^4+1)(2^8+1).(2^(2n)+1)
.
=2^(4n)-1