![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) \(x:\frac{2}{3}=150\)
\(x=150.\frac{2}{3}\)
\(x=100\)
b) \(\frac{35}{9}:x=\frac{35}{6}\)
\(x=\frac{35}{9}.\frac{6}{35}=\frac{2}{3}\)
c,d tương tự
a ) x : 2/3 = 150 c ) x : 4/7 = 180
x = 150 x 2/3 x = 180 x 4/7
x = 100 x = 720/7
b ) 35/9 : x = 35/6 d ) 49/8 : x = 49/5
x = 35/9 : 35/6 x = 49/8 : 49/5
x = 2/3 x = 5/8
![](https://rs.olm.vn/images/avt/0.png?1311)
2 . x - 1300 : ( 65 + 35 ) = 17
2 . x - 1300 : 100 = 17
2. x - 13 = 17
2 . x = 17 + 13
2 . x = 30
x = 30 : 2
x = 15
![](https://rs.olm.vn/images/avt/0.png?1311)
35 . 34 + 35 . 38 + 65 . 75 + 65 . 45 + 35 . 34 =
= 35 . 34 + 35 . 38 + 35 . 34 + 65 . 75 + 65 . 45
= 35 . ( 34 + 38 + 34 ) + 65 . ( 75 + 45 )
= 35 . 110 + 65 . 110
= 110 . ( 35 + 65 )
= 110 . 100
= 11000
Hok tốt!!!!!!!!!!!!!
a) Tính bằng cách hợp lí nhất :
35 . 34 + 35 . 38 + 65 . 75 + 65 . 45 + 35 . 34
= 35 . 34 + 35 . 38 + 35 . 34 + 65 . 75 + 65 . 45
= 35 . ( 34 + 38 + 34 ) + 65 . ( 75 + 45 )
= 35 . 106 + 65 . 120
= 3710 + 7800
= 11510
3 . 25 . 8 + 4 . 37 . 6 + 2 . 38 . 12
= 3 . 8 . 25 + 4 . 6 . 37 + 2 . 12 . 38
= 24 . 25 + 24 . 37 + 24 . 38
= 24 . ( 25 + 37 + 38 )
= 24 . 100
= 2400
b) Tìm số tự nhiên x, biết :
( x - 5 ) ( x + 7 ) = 0
\(\Rightarrow\orbr{\begin{cases}x-5=0\\x+7=0\end{cases}\Rightarrow\orbr{\begin{cases}x=5\\x=-7\end{cases}}}.\)
Vậy .......
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\frac{x-1}{5}+\frac{x-1}{7}+...+\frac{x-1}{37}=0=>\left(x-1\right).\left(\frac{1}{5}+\frac{1}{7}+...+\frac{1}{37}\right)=0\)
mà \(\frac{1}{5}+\frac{1}{7}+...+\frac{1}{37}>0\)
=> x-1 = 0
=> x = 1
Vậy x=1
đúng nha
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{2}{5}\cdot x=\dfrac{4}{7}:\dfrac{2}{3}\)
\(\dfrac{2}{5}\cdot x=\dfrac{6}{7}\)
\(x=\dfrac{6}{7}:\dfrac{2}{5}\)
\(x=\dfrac{15}{7}\)
\(\dfrac{2}{5}.x=\dfrac{4}{7}:\dfrac{2}{3}\)
\(\dfrac{2}{5}.x=\dfrac{4}{7}.\dfrac{3}{2}\)
\(\dfrac{2}{5}.x=\dfrac{6}{7}\)
\(x=\dfrac{6}{7}:\dfrac{2}{5}\)
\(x=\dfrac{6}{7}.\dfrac{5}{2}=\dfrac{15}{7}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Ta có : \(\frac{x}{4}=\frac{y}{7}\)
\(\Rightarrow\frac{x^2}{16}=\frac{y^2}{49}=\frac{3x^2}{48}=\frac{4y^2}{196}=\frac{3x^2-4y^2}{48-196}=\frac{100}{-148}=-\frac{25}{37}\)
Thay vào là ra nhé !:D
Cái chỗ Nguyễn Quang Trung đúng ròi
\(\Rightarrow\hept{\begin{cases}\frac{x}{4}=-\frac{25}{37}\\\frac{y}{7}=-\frac{25}{37}\end{cases}}\Rightarrow\hept{\begin{cases}x=-\frac{100}{37}\\y=-\frac{175}{37}\end{cases}}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
65*x + 35*x = 6000
=> 100*x = 6000
=> x = 6000 : 100
=> x = 60
Vậy x = 60
65 * x + 35 *x = 6000
( 65 + 35) * x = 6000
100 *x=6000
x = 6000 : 100
x = 60
(x-7)x5=35
x-7=35:5
x-7=7
x=7+7
x=14
(x-7) x 5 = 35
x-7 = 35 : 5
x-7 = 7
x = 7 + 7
x = 14.