3^2+4^2=5^2,5^2+12^2=13^2,7^2+24^2=25^2,猜想第n个式子是计算2007^2/2006*2008+1 因式分解 -(a-b)m-a+b=
问题描述:
3^2+4^2=5^2,5^2+12^2=13^2,7^2+24^2=25^2,猜想第n个式子是
计算2007^2/2006*2008+1
因式分解 -(a-b)m-a+b=
答
(2n+1)^2+{[(2n+1)^2-1]/2}^2={[(2n+1)^2+1]/2}^22006*2008=(2007-1)(2007+1)=2007^2-1所以原式=2007^2/(2007^2-1+1)=2007^2/2007^2=1-(a-b)m-a+b= =-(a-b)m-(a-b)=-(a-b)(m+1)