2013/2014*[21/47+19/251 / 11/13]*[1/1+5/7*7/15]

4.24.5^2-(3^3.18+3^3.12)

31.15.7^2.4-31.49.40

1+2+3+4+5+6+7+8+9+10

1+3+5+7+9+11+13+15+19

2+6+10+14+22+23+26+34

5+8+11+14+17+20+23+26+29

1+6+11+16+21+26+31+36+41+47+51

10+13+16+19+22+25+28+31+34+37+40

5+7+9+11+13+15+17+3+8+13+18+23+28

4+7+10+13+16+19+5+9+13+17+21+25

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70=?

Thuc hien phep tinh hop li(neu co the):

1) 69 .113 - 27. 69 + 69 .14 + 31

2) 90 -(2². 25 - 3². 7)

3) 720 - {40.[(120 - 70) :25 + 2³]}

4) 2345 - 1000 :[19 - 2(21 - 18)²]

5) (-23) + 13 + (-17) + 57

6) (-123) + |-13| + (-7)

7) - |-33| +(-15)+ 20 - |45 - 40| - 57

a 12 – 34 b 23 – 47 c 31 – 23 d 9 – 5 e 4 – 15 25 f 23 13 17 57 g 4 . 9 6 . 12 – 7 h 14 6 19 14 19 i 56 – 8. 27 7 j 8 5 . 2 – 3 6 k 4 . 3 125 . 25 8 l 9 6 . 3 – 4 7 m 45. 18 – 15 – 18. 45 – 15 ​

Tính nhanh

A=2/1*5+2/5*9+2/9*13+...+2/97*101+2/101*105

B=4/2*5+4/5*2+4/8*11+...+4/44*47+4/47*50

C=3/1*3*5+3/3*5*7+3/5*7*9+...+3/19*21*23+3/21*23*25

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50=?

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50.