7\3 + 1\2 + -16\32
65\91 + -33\55
36\-84 + 109\450
4/20 + 16\42 + 6\10 + -3\5 + 2\21 + -10\21 + 3\10
5\12 + 3\-16 + 3\4
giải hộ mik với nha
a.4/20 +16/42+6/15+3/5+2/21_10/21+3/20.
b.6/21_-12/44+10/14_1/-4_18/33.
c. -7/11.8/13+ -7/13.5/11
(1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20)*(21*4+6-84)=???...???
(1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20)*(21*4+6-84)=330
a. 4/20+16/42+6/15+3/5+2/21_10/21+3/20. b.6/21_-12/44 +10/14_1/-4_18/33. c.-7/11.8/13+-7/13.5/11
1D 2C 3B 5B 6B
7C 8D 10D 12B 16B
17A 19C 20B 21C 22A
1.D
2.C
3. B
5. B
6. B
7. C
8. D
9. B
10. D
12. B
16. B
17. A
18. B
19. C
20. B
21. C
22. A
a. 4/20+16/42+6/15+3/5+2/21_10/21+3/20. b.6/21_-12/44 +10/14_1/-4_18/33. c.-7/11.8/13+-7/13.5/11
câu 3: rút gọn rồi quy đồng
a, 12/36 và -16/ 20 b, 21/ 105 và 35/ 150
Câu 4:
a, 3/10 + 5/10 b, [-27] . 36+ 64 . [-27] + 23 . [ -100]
c, 5/8 + 3/ 12 d, -2/17 + 3/19 + -15/ 17 + 16/19 + 5/6
mai mình thi rồi, các bạn giúp mình với
Câu 4:
d) Ta có: \(\dfrac{-2}{17}+\dfrac{3}{19}+\dfrac{-15}{17}+\dfrac{16}{19}+\dfrac{5}{6}\)
\(=\left(-\dfrac{2}{17}-\dfrac{15}{17}\right)+\left(\dfrac{3}{19}+\dfrac{16}{19}\right)+\dfrac{5}{6}\)
\(=-1+1+\dfrac{5}{6}=\dfrac{5}{6}\)
Câu 3: rút gọn phân số
a, 12/36 và -16/ 20 b, 21/ 105 và 35/ 150
Câu 4:
a, 3/10 + 5/10 b, [-27] . 36+ 64 . [-27] + 23 . [ -100]
c, 5/8 + 3/ 12 d, -2/17 + 3/19 + -15/ 17 + 16/19 + 5/6
Câu 3:
a) \(\dfrac{12}{36}=\dfrac{12:12}{36:12}=\dfrac{1}{3}\)
\(\dfrac{-16}{20}=\dfrac{-16:4}{20:4}=\dfrac{-4}{5}\)
b) \(\dfrac{21}{105}=\dfrac{21:21}{105:21}=\dfrac{1}{5}\)
\(\dfrac{35}{150}=\dfrac{35:5}{150:5}=\dfrac{7}{30}\)
Câu 4:
a) \(\dfrac{3}{10}+\dfrac{5}{10}=\dfrac{3+5}{10}=\dfrac{8}{10}=\dfrac{4}{5}\)
b) Ta có: \(\left(-27\right)\cdot36+64\cdot\left(-27\right)+23\cdot\left(-100\right)\)
\(=\left(-27\right)\cdot\left(64+36\right)+23\cdot\left(-100\right)\)
\(=-27\cdot100-23\cdot100\)
\(=100\left(-27-23\right)\)
\(=-50\cdot100=-5000\)
c) \(\dfrac{5}{8}+\dfrac{3}{12}=\dfrac{15}{24}+\dfrac{6}{24}=\dfrac{21}{24}=\dfrac{7}{8}\)
d) Ta có: \(\dfrac{-2}{17}+\dfrac{3}{19}+\dfrac{-15}{17}+\dfrac{16}{19}+\dfrac{5}{6}\)
\(=\left(-\dfrac{2}{17}+\dfrac{-15}{17}\right)+\left(\dfrac{3}{19}+\dfrac{16}{19}\right)+\dfrac{5}{6}\)
\(=-1+1+\dfrac{5}{6}\)
\(=\dfrac{5}{6}\)
bài 1:tính số hạng có trong các tổng sau:
1.1-2+3-4+5-6+7-8
2.1-3+5-7+9-11+13-15
3.-1+3-5+7-9+11-13+15
4.2-4+6-8+10-12+14-16+18-20
5.-2+4-6+8-10+12-14+16-18+20
6.2-5+8-11+14-17+20-23+26
7.-1+5-9+13-17+21-25+29-33+37
8.1-5+9-....-81+85-89+93
9.2-4+6-8+....+202-204
10.1-6+11-16+21-....+176-181
C=4/40+16/42+6/15+-3/5+2/21+-10/21+3/20
C = \(\frac{4}{40}+\frac{16}{42}+\frac{6}{15}+\left(\frac{-3}{5}\right)+\frac{2}{21}+\left(\frac{-10}{21}\right)+\frac{3}{20}\)
C = \(\left(\frac{4}{40}+\frac{3}{20}\right)+\left(\frac{16}{42}+\frac{-10}{21}+\frac{2}{21}\right)+\left(\frac{6}{15}+\frac{-3}{5}\right)\)
C = \(\frac{1}{4}+0+\frac{-1}{5}\)
C = \(\frac{1}{20}\)