4×102-2×49 =408-2×49 =408-98 =310
25×(2+4) =25×2+25×4 =50+100 =150
12×5+8 =60+8 =68
99×101 =99×(100+1) =99×100+99×1 =9900+99
5. 25×(78×4) =25×4×78 =100×78 =7800
4×102-2×49 =408-2×49 =408-98 =310
25×(2+4) =25×2+25×4 =50+100 =150
12×5+8 =60+8 =68
99×101 =99×(100+1) =99×100+99×1 =9900+99
5. 25×(78×4) =25×4×78 =100×78 =7800
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