Ko bết

9/10

17/36

7/6

19/12

67/56

12/35

11/8

7/12

25/24

73/21

17/30

2

ok chưa bạn!

a) \(\dfrac{3}{4}-\dfrac{1}{8}=\dfrac{6}{8}-\dfrac{1}{8}=\dfrac{6-1}{8}=\dfrac{5}{8}\)

b) \(\dfrac{2}{6}-\dfrac{5}{18}=\dfrac{6}{18}-\dfrac{5}{18}=\dfrac{6-5}{18}=\dfrac{1}{18}\)

c) \(\dfrac{2}{5}-\dfrac{3}{20}=\dfrac{8}{20}-\dfrac{3}{20}=\dfrac{8-3}{20}=\dfrac{5}{20}=\dfrac{1}{4}\)

5+5+5+5+5+5+5+5+5-6-6-6-6-6=5*9-[6*5]

                                             =45-30

                                             =15

12+12+12+12+12+12+12+12+12+12=12*10

                                                     =120

đóng ngoặc 6*5 để làm j vậy bn

???

???

=5 x 9 = 45 

=6 x 5 = 30

45 - 30 = 15

12 x 10 = 120

35/36

3/2

31/24

8/9 - 2/6 + 5/12 = 34/36 - 12/36 + 15/36= 35/36

5/12 + 3/4 + 1/3 = 5/12 + 9/12 + 4/12 = 3/2

1/12 + 5/6 + 3/8= 2/24 +20/24 +9/24 = 31/24

\(\frac{5}{12}+\frac{5}{6}-\frac{3}{4}\)

\(=\frac{5}{12}+\frac{10}{12}-\frac{9}{12}\)

\(=\frac{5+10-9}{12}\)

\(=\frac{6}{12}\)

\(=\frac{1}{2}\)

\(\frac{3}{5}+\frac{6}{4}+\frac{5}{2}\)

\(=\frac{24}{40}+\frac{60}{40}+\frac{100}{40}\)

\(=\frac{24+60+100}{40}\)

\(=\frac{184}{40}\)

Tự rứt gọn nha ! 

\(1-\left(\frac{1}{5}+\frac{1}{2}\right)\)

\(=1-\frac{1}{5}-\frac{1}{2}\)

\(=\frac{4}{5}-\frac{1}{2}\)

\(=\frac{3}{10}\)

\(\frac{7}{8}\times3+\frac{5}{12}\)

\(=\frac{21}{8}+\frac{5}{12}\)

\(=\frac{73}{24}\)

\(\frac{5}{12}+\frac{5}{6}-\frac{3}{4}\)

= \(\frac{5}{12}+\frac{10}{12}-\frac{9}{12}\)

= \(\frac{15}{12}-\frac{9}{12}\)

= \(\frac{6}{12}\)

\(1-\left(\frac{1}{5}+\frac{1}{2}\right)\)

= \(1-\left(\frac{2}{10}+\frac{5}{10}\right)\)

= \(1-\frac{7}{10}\)

= \(\frac{10}{10}-\frac{7}{10}\)

= \(\frac{3}{10}\)

a: Ta có: \(\left(8\cdot5^7+5^6-5^5\right):5^5\)

\(=8\cdot5^2+5-1\)

\(=200+4=204\)

b: Ta có: \(\left(9^{30}-27^{19}\right):3^{57}+\left(125^9-25^{12}\right):5^{24}\)

\(=3^{60}:3^{57}-3^{57}:3^{57}+5^{27}:5^{24}-5^{24}:5^{24}\)

\(=27-1+125-1\)

=150

a. (8,5⁷ - 5⁵ + 5⁶) : 5⁵

= (8,5⁷ : 5⁵) - (5⁵ : 5⁵) + (5⁶ : 5⁵)

= 1,7² - 1 + 5

= 2,89 - 1 + 5

= 6,89

b. (9³⁰ - 27¹⁹) : 3⁵⁷ + (125⁹ - 25¹²) : 5²⁴

= (9³⁰ : 3⁵⁷) - (27¹⁹ : 3⁵⁷) + (125⁹ : 5²⁴) - (25¹² : 5²⁴)

= 3³ - 1 + 125 - 1

= 27 - 1 + 125 - 1

= 150

c. (10¹² + 5¹¹ . 2⁹ - 5¹³ - 2⁸) : 4 . 5⁵ . 10⁶

= (10¹² + 2,5 , 10¹⁰ - 5¹³ - 2⁸) : 1,25 . 10¹⁰

= (10¹² : 1,25 . 10¹⁰) + (2,5 . 10¹⁰ : 1,25 . 10¹⁰) - (5¹³ : 1,25 . 10¹⁰) - (2⁸ : 1,25 . 10¹⁰)

= 80 + 2 - \(\dfrac{25}{256}\) - \(\dfrac{1}{48828125}\)

= 81,90234373 \(\approx\) 82

khó quá mk giải miết mà không ra

khó vãi

5/-6+-5/12 +7/18 = -31/36

2/9+-3/10+-7/10 = 2/9+(-3/10+-7/10)=2/9+(-1)=7/9

-11/6 +2/5 +-1/6 =2/5 +(-11/6+-1/6)=2/5 + -2 =-8/5

-5/8+12/7+13/8+2/7 =(-5/8+13/8)+(12/7+2/7)=1+2=3