Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1.
=3/5x(3/7+4/7)+2/5x(13/9-4/9)
=3/5x1+2/5x1
=3/5+2/5
=1
2.Xx(3/4+4/5)=7/10
Xx31/20=7/10
X =7/10:31/20
X =14/31
\(\frac{3}{5}\cdot\frac{3}{7}+\frac{3}{5}\cdot\frac{4}{7}+\frac{2}{5}\cdot\frac{13}{9}-\frac{2}{5}\cdot\frac{4}{9}\)
\(=\frac{3}{5}\cdot\left(\frac{3}{7}+\frac{4}{7}\right)+\frac{2}{5}\cdot\left(\frac{13}{9}-\frac{4}{9}\right)\)
\(=\frac{3}{5}\cdot1+\frac{2}{5}\cdot1\)\(=\frac{3}{5}+\frac{2}{5}=1\)
_________________________________________
\(\frac{3}{4}\cdot x+\frac{4}{5}\cdot x=\frac{7}{10}\)
\(\left(\frac{3}{4}+\frac{4}{5}\right)\cdot x=\frac{7}{10}\)
\(\frac{31}{20}\cdot x=\frac{7}{10}\)
\(x=\frac{7}{10}:\frac{31}{20}\)
\(x=\frac{14}{31}\)
Câu 1:
0,9 x 218 x 2 + 0,18 x 4290 + 0,6 x 353 x 3
= 9/10 x 436 + 9/50 x 4290 + 6/10 x 1059
= 9 x 43,6 + 9 x 85,8 + 6 x 105,9
= 3 x 130,8 + 3 x 257,4 + 3 x 211,8
= 3 x ( 130,8 + 257,4 + 211,8 )
= 3 x 600
= 1800
Câu 2:
3/4 x X + 1/2 x X - 15 = 35
X x ( 3/4 + 1/2 ) - 15 = 35
X x ( 3/4 + 1/2 ) = 50
X x 5/4 = 50
X = 40
VẬy X = 40
Trả lời
a)(136,5-x).1,2=5,4
136,5-x =5,4:1,2
136,5-x =4,5
x =136,5+4,5
x =141
b)18:(372:3.x-1)=6
372:3x-1 =18:6
372:3x-1 =3
372:3x =3+1
372:3x =4
3x =372:4
3x =93
x =93:3
x =31
c)[(6.x-39):7].4=12
(6x-39):7 =12:4
(6x-39):7 =3
6x-39 =3.7
6x-39 =21
6x =21+39
6x =60
x =60:6
x =10
d)2448:[119-(x-6)]=24
119-(x-6)=2448:24
119-(x-6)=102
x-6 =119-102
x-6 =17
x =17+6
x =23
Chúc bạn học tốt !
a, ( 136,5 - X ) x 1,2 = 5,4
=> 136,5 - X = 5,4 : 1,2
=> 136,5 - X = 4,5
=> X = 136,5 - 4,5
=> X = 132
b, hình như sai đề bạn ơi
c, [ ( 6 x X - 39 ) : 7 ] x 4 = 12
=> ( 6 x X - 39 ) : 7 = 12 : 4
=> ( 6 x X - 39 ) :7 = 3
=> 6 x X - 39 = 3 x 7
=> 6 x X - 39 = 21
=> 6 x X = 60
=> X = 60 : 6
=> X = 10
d, 2448 : [ 119 - ( x - 6 ) ] = 24
=> 119 - ( x - 6 ) = 2448 : 24
=> 119 - ( x - 6 ) = 102
=> x - 6 = 119 - 102
=> x - 6 = 17
=> x = 17 + 6
=> x = 23
Nhân thêm 2
=>(13-11/11x13+...+21-19/19x21)-x+221/231=4/3
=>(13/11x13-11/11x13+...+21/19x21-19/19x21)-x+221/231=4/3
=>(1/11-1/13+...+1/18-1/21)-x+221/231=4/3
=>(1/11-1/21)-x+221/231=4/3
=>10/231-x+221/231=4/3
=>10/231+221/231-x=4/3
=>231/231-x=4/3
=>1-x=4/3
=>x=1-4/3=-1/3
a) ( x - 3 ) x 5 = 21 Đáp án 7,2
b) 36 - 8 x x = 26 : đs 1,25
c) 3- 7,2 = 1,56 Đs ...
d) x / 6 x 4 = 1,248 ĐS 1.872
\(x+\frac{x}{3}=24\)
\(\Leftrightarrow\frac{3x}{3}+\frac{x}{3}=24\)
\(\Leftrightarrow\frac{3x+x}{3}=24\)
\(\Leftrightarrow\frac{x\left(3+1\right)}{3}=24\)
\(\Rightarrow4x=24\times3\)
\(\Leftrightarrow4x=72\)
\(\Leftrightarrow x=18\)
P/s tham khảo nha
\(x+\frac{x}{3}=24\)
\(\frac{3x}{3}+\frac{x}{3}=24\)
\(\frac{4x}{3}=\frac{72}{3}\)
\(\Rightarrow4x=72\)
\(x=72:4\)
\(x=18\)