tính

a. -3/4 x 12/-5 x (-25/6)

b. -2 x -38/21 x -7/4 x (-3/8)

c. (11/12: 33/16) x 3/5

d. 7/23 x [(-8/6)- 45/18]

a) -3/4 . 12/5 . (25/6)                                   b) (-2) . - 38/21 . -7/4 . (-3/8)

c) (11/12 : 33/16) .3/5                                  d) 7/23 . ((-8/6) - 45/18)

(-2) x -38/21 x -7/4 x (-3/8)

(11/12 : 33/16) x 3/5

7/23 x [(-8/6) - 45/18]

AI LÀM ĐÚNG CHO 1 LIKE VÀ XIN CẢM TẠ

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.

Tính:
a) \(\dfrac{-3}{4}.\dfrac{12}{-5}.\left(-\dfrac{25}{6}\right);\)               b) \(\left(-2\right).\dfrac{-38}{21}.\dfrac{-7}{4}.\left(-\dfrac{3}{8}\right);\)
c) \(\left(\dfrac{11}{12}:\dfrac{33}{16}\right).\dfrac{3}{5};\)                     d) \(\dfrac{7}{23}.\left[\left(-\dfrac{8}{6}\right)-\dfrac{45}{18}\right].\)

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

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+149+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39*100

câu trả lời cho câu hỏi của Huong Le Thị Lan: 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.

=(1+32)+(2+31)+(3+30)+(4+29)+(5+28)+(6+27)+(7+26)+(8+25)+(9+24)+(10+23)+(11+22)+(12+21)+(13+20)+(14+19)+(15+18)+(16+17)

=33+33+33+33+33+33+33+33+33+33+33+33+33+33+33+33.    =33.16 (dấu chấm là dấu nhân)=528