Question

Câu 1: Dùng tính chất phép toán để tính nhanh:

a) 17. 25                                             b) 281+129+219

c)2^3 . 2^2+ 5^5 : 5^3                           d) 29 . 31+66 .69+31 . 37

Answer 1

a)17.25=25.17=25.(1+16)=25.1+25.16=25+25.4.4=25+100.4=25+400=425

b)281+129+219=281+219+129=500+129=629

c)2³.2²+5⁵:5³=2³⁺²+5^5-3=2⁵+5²=32+25=57

d)29.31+66.69+31.37=31.(29+37)+66.69=31.66+66.69=66.(31+69)=66.100=6600

Answer 2

a. 17.25 = 425

b. 281+129+219 = (281 + 219) + 129 = 500 + 129 = 629

c. 2³.2²+5⁵:5³ = 2⁵+5²=32+25=57

d. 29.31+66.69+31.37

= 29.31+31.37+66.69

= 31.(29+37)+66.69

= 31.66+66.69

= 66.(31 + 69)

= 66.100

= 6600

Answer 3

a)17.25=425

b)281+129+219=(281+219)+129=1000+129=1129

c)2^3.2^2+5^5:5^3=2^(3+2) +5^(5-3)=2^5+5^2=32+25=57

d)29.31+66.69+31.37=31(29+37)+66.69=31.66+66.69=66(31+69)=66.100=3100

Answer 4

bn ơi mk nhầm câu b) 281+219=500+129=629