(1)原式=(50+47)(50-47)
=600
(2)原式=14×(15×2/3×1/3)
=140 /3
(3)原式=(1-1/2)(1+1/2)(1-1/3)(1+1/3)·····(1-1/10)(1+1/10)
=1/2×3/2×2/3×4/3···9/10×11/10
=11/20
(1)原式=(50+47)(50-47)
=600
(2)原式=14×(15×2/3×1/3)
=140 /3
(3)原式=(1-1/2)(1+1/2)(1-1/3)(1+1/3)·····(1-1/10)(1+1/10)
=1/2×3/2×2/3×4/3···9/10×11/10
=11/20