Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) 1160 : {145.[1500 : (22.53) - 194 : 97]}
= 1160 : {145.[1500 : (4.125) - 2]}
= 1160 : {145.[1500 : 500 - 2]}
= 1160 : {145.[3 - 2]}
= 1160 : 145
= 8
b) 1245 - {102 - 320 : [(794 - 111.6) : 22 ]}
= 1245 - {100 - 320 : [(794 - 666) : 22 ]}
= 1245 - {100 - 320 : [128 : 22 ]}
= 1245 - {100 - 320 : 32}
= 1245 - {100 - 10}
= 1245 - 90
= 1155
c) 912 : 322 . {53 - [(139 - 67).5] : 10}
= (32)12 : 322 . {125 - [72 . 5] : 10}
= 32.12 : 322 . {125 - 360 : 10}
= 324 : 322 . {125 - 36}
= 32 . 89
= 9.89
= 301
Ta có: \(\frac{A}{B}=\frac{1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{4042}}{1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{4041}}\)
\(=\frac{\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{4041}\right)+\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{4042}\right)}{1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{4041}}\)
\(=1+\frac{\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{4042}}{1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{4041}}\)
Ta thấy \(1>\frac{1}{2}\) ; \(\frac{1}{3}>\frac{1}{4}\) ; ... ; \(\frac{1}{4041}>\frac{1}{4042}\)
\(\Rightarrow\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{4042}< 1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{4041}\)
\(\Rightarrow\frac{\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{4042}}{1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{4041}}< 1\)
\(\Rightarrow1+\frac{\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{4042}}{1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{4041}}< 1+1< 1+\frac{2021}{2020}=1\frac{2021}{2020}\)
\(\Rightarrow\frac{A}{B}< 1\frac{2021}{2020}\)
5 - ( 12 - x ) = 129 - ( 6 + 129 )
5 - 12 + x = 129 - 6 - 129
( -7 ) + x = ( -6)
x = ( - 6 ) + 7
x = 1
Vậy x = 1
5-(12-x)=129-(6+129)
5-(12-x)=129-135
5-(12-x)=-6
12-x =5-(-6)
12-x=11
x=12-11
x=1
20.11x194+20.11x805+20.11
=20.11x(194+805+1)
=20.11x1000=20110
X x 3.4 +X x1.2=23
X x( 3.4+1.2)=23
X x 4.6=23
X=23 :4.6=5
* \(20,11.194+20,11.805+20,11\)
\(=20,11.\left(194+805+1\right)\)
\(=20,11.1000\)
\(=20110\)
* \(x.3,4+x.1,2=23\)
\(\Leftrightarrow x.\left(3,4+1,2\right)=23\)
\(\Leftrightarrow x.4,6=23\)
\(\Leftrightarrow x=23:4,6\)
\(\Leftrightarrow x=5\)
(Nhớ k cho mình với nha!)
Đầu tiên là phá ngoặc
-129 -35+x =55
-164+x=55
x=55+164
x=219
194 * (129 : x) = 4042
129 : x = 4042 : 194
129 : x = 2021/97
x = 129 : 2021/97
x = 129 * 97/2021
x = 291/47
Vậy x = 291/47
Chúc bạn học tốt
\(129:x=4042:194\)
\(129:x=\frac{2021}{97}\)
\(x=\frac{291}{47}\)