Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a, 28 . (-2).3 - { 136 + [54 - 28 : (69 - 71).2 ]}
=-168- { 136 + [54 - 28 : (-2).2 ]}
=-168 - [136 + (54+28)]
=-168 - 218
=-386
b) 203.46-203.37+203
=203.46-203.37+203.1
=203.(46-37+1)
=203.10
=2030
c)21+23+25+27+29-31-33-35-37-39
=(21-31)+(23-33)+(25-35)+(27-37)+(29-39)
= -10 + (-10) + (-10) + (-10) + (-10)
=-50
d) 18.17-3.6.17
=18.17-18.17
= 0
e,33. ( 107- 112) - 107 . ( 33- 112)
=33.107- 33.112- 107.33+107.112
=(33.107- 33.112- 107.33)+107.112
=33(107-112-107)+107.112
=-33.112+107.112
=112.(-33+107)
=112.74
=8288
CHÚC BẠN MAY MẮN
1/2+1/3+1/6+1/12+1/15+1/20+1/30+1/35+1/42+1/63
=(1/2+1/6+1/12+1/20+1/30+1/42) + (1/3 +1/15+1/35+1/63)
=(1/1.2+1/2.3+1/3.4+1/4.5+1/5.6+1/6,7)+(1/1.3+1/3.5+1/5.7+1/7.9)
=(1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6 -1/7) + 1/2.(2/1.3+2/3.5+2/5.7+2/7,9)
=(1-1/7)+ 1/2.(1-1/3+1/3-1/5+1/5-1/7+1/7-1/9)
=6/7+1/2 .(1-1/9)
=6/7+1/2.(8/9)
=6/7+4/9
=82/63
học tốt
1/ 12 . 194 + 6 . 437 . 2 + 3 . 369 . 4
= 12 . 194 + 12 . 437 + 12 . 369
= 12(194 + 437 + 369)
= 12 . 1000
= 12000
2/ 1 + 5 + 9 + 19 + ... + 61 + 65 . 2 - 26
= (1 + 61) + (5 + 57) + ... + (29 + 33) + 130 - 26
= 62 . 8 + 130 - 26
= (496 - 26) + 130
= 470 + 130
= 600
3/ (1374 x 57 + 687 x 86) : (26 x 13 + 74 x 14)
= (1374 x 57 + 1374 x 43) : (26 x 13 + 74 x 13 + 74)
= (1374 x 100) : (13 x 100 + 74)
= 137400 : 1374 = 100
1) 6/7 = -24/-28
2) -21/35=147/-245
3) -594/2310 = 9/-35
4) -1313 k= 131313/373737
5) 111111/5005 = -111/5
6) 5/7 = 1+2+3+4+5/1+2+3+4+5+6
\(A=\dfrac{1}{5}+\dfrac{3}{35}+\dfrac{1}{21}+\dfrac{1}{33}+\dfrac{3}{143}+\dfrac{1}{65}\)
\(=\left(\dfrac{1}{5}+\dfrac{1}{21}+\dfrac{3}{35}\right)+\left(\dfrac{1}{33}+\dfrac{1}{143}+\dfrac{1}{65}\right)\)
\(=\dfrac{21+5+9}{105}+\dfrac{13+3}{429}+\dfrac{1}{65}\)
\(=\dfrac{1}{3}+\dfrac{1}{65}+\dfrac{16}{429}\)
\(=\dfrac{276}{715}\)