tính
\(\frac{-34}{37}.\frac{74}{-85}\)
Tính:
a,\(\frac{-1}{39}+\frac{-1}{52}\) b,\(\frac{-6}{9}+\frac{-12}{16}\) c,\(\frac{-2}{5}-\frac{-3}{11}\) d,\(\frac{-34}{37}\cdot\frac{74}{-85}\) e,\(\frac{-5}{9}:\frac{-7}{18}\)
-34/37 . 74/- 85
Ta có:\(-\frac{34}{37}.\frac{74}{-85}=\frac{\left(-34\right).74}{37.\left(-85\right)}=\frac{\left(-17\right).2.2.37}{37.\left(-17\right).5}=\frac{4}{5}\)
a) \(\frac{-1}{39}+\frac{-1}{52}\) b)\(\frac{-6}{9}+\frac{-12}{16}\) C)\(\frac{-2}{5}-\frac{-3}{11}\) D) \(\frac{-34}{37}\times\frac{74}{-85}\)
a, \(\frac{-1}{39}+\frac{-1}{52}=\frac{-61}{468}\)
b, \(-\frac{9}{6}+-\frac{12}{16}=-\frac{9}{4}\)
\(c,-\frac{2}{5}--\frac{3}{11}=-\frac{7}{55}\)\
\(-\frac{34}{37}\cdot\frac{74}{-58}=\frac{34}{29}\)
Tính gia trị biểu thức sau bàng cách hợp lý nhất (nếu có thể): \(\frac{34}{7\cdot13}+\frac{51}{13\cdot22}+\frac{85}{22\cdot37}+\frac{68}{37\cdot49}\)
-34/37 . 74/-85
-5/9 : -7/18
= 0,8
= 1.42857142857
Máy tính cả thôi, hi hi
Bài 1: a,(-34)/37×74/-85
B, -5/9÷-7/18
a) \(\frac{-34}{37}\)\(\times\frac{74}{-85}\)\(\frac{-34}{37}\times\frac{74}{-85}=\frac{-34\times74}{37\times\left(-85\right)}=\frac{-34\times2}{1\times\left(-85\right)}=\frac{34}{85}\)
b) \(\frac{-5}{9}:\frac{-7}{18}=\frac{-5}{9}\times\frac{-18}{7}=\frac{-4\times\left(-18\right)}{9\times7}=\frac{-4\times\left(-2\right)}{1\times7}=\frac{8}{7}\)
Tính nhẩm:
85 – 5 = … | 74 – 3 = … | 56 – 1 = … |
85 – 50 = … | 74 – 30 = … | 56 – 10 = … |
85 – 15 = … | 74 – 34 = … | 56 – 56 = … |
Lời giải chi tiết:
85 – 5 = 80 | 74 – 3 = 7 | 56 – 1 = 55 |
85 – 50 = 35 | 74 – 30 = 44 | 56 – 10 = 46 |
85 – 15 = 70 | 74 – 34 = 40 | 56 – 56 = 0 |
1) tính:
a) \(\frac{-1}{39}\)+\(\frac{-1}{52}\) b) \(\frac{-6}{9}+\frac{-12}{16}\)
c) \(\frac{-2}{5}-\frac{-3}{11}\) d) \(\frac{-34}{37}.\frac{74}{-85}\) e) \(\frac{-5}{9}:\frac{-7}{18}\)
cho A=\(\frac{34}{7\cdot13}+\frac{51}{13\cdot22}+\frac{85}{22\cdot37}+\frac{68}{37\cdot49}\)
cho B=\(\frac{39}{7\cdot6}+\frac{65}{16\cdot31}+\frac{52}{31\cdot43}+\frac{26}{43\cdot49}\)
tính\(\frac{A}{B}\)