... linh Thi gian lm bi: 120 pht Cõu 1: (2) Rt gn A= x x2 x + x 20 Cõu (2) Ba lp 7A,7B,7C cỳ 94 hc sinh tham gia trng cõy Mi hc sinh lp 7A trng c cõy, Mi hc sinh lp 7B trng c cõy, Mi hc sinh lp 7C ... 10 Cõu 2: ((3) a 130 hc sinh thuc lp 7A, 7B, 7C ca mt trng cựng tham gia trng cõy Mi hc sinh ca lp 7A, 7B, 7C theo th t trng c 2cõy, cõy, cõy Hi mi lp cú bao nhiờu hc sinh tham gia trng cõy? ... x2= - 2/3 1 1 1 1 + + + 20 07 ; S = + + 2006 7 7 7 7 7 S= (0.5) (0,5) 99 100 + + + + = + + + b, 2! 3! 4! 100! 2! 3! 100! < (0,5) = 100! 20 07 (0,25) 20 07 (0,5) c, Ta cú n+2 n+ + 3n...