Question

Tính nhanh :

a, 15.18     b,25.24     c,125.72    d,55.14

Answer 1

a) 15 . 18 = (10+5).18 = 180 + 90= 270

b)  25.24   = (20+5).24 = 480 + 120 = 600

c)125.72 = (100+25) . 72 = 7200 + 1800 = 9000

d) 55.14 = 55. ( 10+4) = 550 + 220= 770

Answer 2

a. 15.18=3.5.3.6=(3.3).(5.6)=9.30=270

b. 25.24=5.5.6.4=(5.4).(5.6)=20.30=600

c. 125.72=5^3.2^3.9=(5.2)^3.9=1000.9=9000

d. 55.14=5.11.7.2=(7.11).(5.2)=77.10=770