=-3720

đồ bấm máy tính ko chấp

* 100 là cái gì vậy .nhân à

79600 nha

a)\(\frac{27}{5}\text{x}\frac{91}{12}\text{x}\frac{125}{9}\text{x}\frac{96}{13}=\frac{27}{9}\text{x}\frac{91}{13}\text{x}\frac{125}{5}\text{x}\frac{96}{12}=3\text{x}7\text{x}25\text{x}8\)

Đến đây tự tính nha !

b)\(\frac{2539}{35}\text{x}\frac{7}{90}+\frac{561}{35}\text{x}\frac{7}{90}=\frac{7}{90}\text{x}\left(\frac{2539}{35}+\frac{561}{35}\right)=\frac{7}{90}\text{x}\frac{3100}{35}=\frac{3100}{90}\text{x}\frac{7}{35}=\frac{310}{9}\text{x}\frac{1}{5}=\frac{62}{9}\)

1. 27/5 x 91/12 x 125/9 x 96/13

2. 2539/35 x 7/90 + 561/35 x 7/90

3. 31/7 : (2/5 x 31/7)

4. (29 x 15/23 x 36/29) : 5/23

BAI 1 ; 

Bài 2: 

a, \(\dfrac{5}{23}\) \(\times\) \(\dfrac{17}{26}\) + \(\dfrac{5}{23}\) \(\times\) \(\dfrac{9}{26}\) 

= \(\dfrac{5}{23}\) \(\times\) ( \(\dfrac{17}{26}\) + \(\dfrac{9}{26}\))

= \(\dfrac{5}{23}\) \(\times\) \(\dfrac{26}{26}\)

= \(\dfrac{5}{23}\) 

b, \(\dfrac{3}{4}\) \(\times\) \(\dfrac{7}{9}\) + \(\dfrac{7}{4}\)  \(\times\) \(\dfrac{3}{9}\)

= \(\dfrac{7}{12}\) + \(\dfrac{7}{12}\)

= \(\dfrac{14}{12}\)

= \(\dfrac{7}{6}\)

Ghi lời giải giúp mình☺☺☺☺☺

Minh bao cao roi /!\

Câu 1:

\(x\) + 56 x 2 - [32 + 16 x 3 : 6 - 15] = 0

\(x\) + 112 - [32 + 48 : 6 - 15] = 0

\(x\) + 112 - [32 + 8 - 15] = 0

\(x\) + 112 - [40 - 15] = 0

\(x\) + (112 - 25) = 0

\(x\) + 87 = 0

\(x=-87\)

Lớp 5 chưa học số âm, em nhé.

420 + 65 x 4 = (\(x\) + 175) : 5 + 30

420 + 260 = (\(x\) + 175) : 5 + 30

680 = (\(x\) + 175) : 5 = 30

(\(x\) + 175) : 5 = 680 - 30

(\(x\) + 175) : 5 = 650

\(x\) + 175 = 650 x 5

\(x\) + 175 = 3250

\(x\) = 3250 - 175

\(x\) = 3075