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1.0.25^2008×4^2009-8^100×0.5^3002.50^2-49^2+48^2-47^2+…+2^2-1^2同上3.已知X^3-6X^2+11X-6=(x-1)(x^2+mx+n)求MN的值

题目详情
1.0.25^2008×4^2009-8^100×0.5^300
2.50^2-49^2+48^2-47^2+…+2^2-1^2 同上
3.已知X^3-6X^2+11X-6=(x-1)(x^2+mx+n) 求MN的值
▼优质解答
答案和解析
1.0.25^2008×4^2009-8^100×0.5^300
=(0.25×4 )^2008×4-(8×0.5^3)^100
=4-1
=3
2.50^2-49^2+48^2-47^2+…+2^2-1^2 (每两项做完全平方差)
=(50-49)(50+49)+(48-47)(48+47)+…+(2-1)(2+1)
= 99 + 95 + ...+ 3 = (99+3)*25/2
= 1275
3.X^3-6X^2+11X-6
= (x-1)(x^2-5x+6)=(x-1)(x^2+mx+n)
所以 m = -5; n = 6; mn = -30