Tìm x: (hứa tick)
a) 4/X = 2/9
b) X x 0,3 = 3/5
c) X : 1,1 = 3/4
d) 121,8 : X = 5/9
giúp với ạ,cần gấp.hứa tick
a,4/x = 2/9
Ⅹ x 0,3 = ⅗
c X :, 1,1 = 3/4
d,121,8 : x = 5/9
a) \(\dfrac{4}{x}=\dfrac{2}{9}\)
\(x=\dfrac{\left(4\times9\right)}{2}\)
\(x=\dfrac{36}{2}\)
\(x=18\)
b) \(x\times0,3=\dfrac{3}{5}\)
\(x\times\dfrac{3}{10}=\dfrac{3}{5}\)
\(x=\dfrac{3}{5}:\dfrac{3}{10}\)
\(x=\dfrac{3}{5}\times\dfrac{10}{3}\)
\(x=\dfrac{30}{15}\)
\(x=2\)
c) \(1,1=\dfrac{3}{4}\) câu này thiếu
d) \(121,8:x=\dfrac{5}{9}\)
\(\dfrac{609}{5}:x=\dfrac{5}{9}\)
\(x=\dfrac{609}{5}:\dfrac{5}{9}\)
\(x=\dfrac{609}{5}\times\dfrac{9}{5}\)
\(x=\dfrac{5481}{25}\)
c) \(x:1,1=\dfrac{3}{4}\)
\(x:\dfrac{11}{10}=\dfrac{3}{4}\)
\(x=\dfrac{3}{4}\times\dfrac{11}{10}\)
\(x=\dfrac{33}{40}\)
Bài 1:Tính giá trị biểu thức
a, (27,5 x 0,1 + 2,5 x 0,1) x 2
b, 82,37 + 36 + 63 x 82,37 + 82,37
c, (27,54 x 1,1 - 279,24 x 0,1) : 0,3
Bài 2: Tìm x
a, X : 8 + X x 8 - 56,78 = 69,11 x 2
b, X + X : 5 x 7,5 + X : 2 x 9 = 315
c, X x 4 - X : 4 - 24,76 = 190,48 : 2
Giúp em với mọi người ơi, em cần gấp lắm, em hứa sẽ tick cho ai nhanh nhất
a, (27,5 x 0,1 + 2,5 x 0,1) x 2
=(0,1 x (2,5+27,5)) x 2
=(0,1 x 30) x 2
=3 x 2
=6
b, 82,37 + 36 + 63 x 82,37 + 82,37
Khó quá ! chắc bạn chép sai đề
c, (27,54 x 1,1 - 279,24 x 0,1) : 0,3
hình nhưu lại sai đề
Làm hộ mik b2 thôi được ko, mik sẽ tự làm b1 mà
1.tính thuận tiện
a. 2/3 x 4/5 + 1/3 x 4/5
b. 2/3 x 4/5 - 1/3 x 4/5
c. 1/2 : 3/4 + 1/6 : 3/4
d. 1/2 : 3/4 - 1/6 : 3/4
a)\(\dfrac{2}{3}.\dfrac{4}{5}+\dfrac{1}{3}.\dfrac{4}{5}=\left(\dfrac{2}{3}+\dfrac{1}{3}\right).\dfrac{4}{5}=1.\dfrac{4}{5}=\dfrac{4}{5}\)
b)\(\dfrac{2}{3}.\dfrac{4}{5}-\dfrac{1}{3}.\dfrac{4}{5}=\left(\dfrac{2}{3}-\dfrac{1}{3}\right).\dfrac{4}{5}=\dfrac{1}{3}.\dfrac{4}{5}=\dfrac{4}{15}\)
a) \(\dfrac{2}{3}\times\dfrac{4}{5}+\dfrac{1}{3}\times\dfrac{4}{5}=\dfrac{4}{5}\times\left(\dfrac{2}{3}+\dfrac{1}{3}\right)=\dfrac{4}{5}\times1=\dfrac{4}{5}\)
b) \(\dfrac{2}{3}\times\dfrac{4}{5}-\dfrac{1}{3}\times\dfrac{4}{5}=\dfrac{4}{5}\times\left(\dfrac{2}{3}-\dfrac{1}{3}\right)=\dfrac{4}{5}\times\dfrac{1}{3}=\dfrac{4}{15}\)
c) \(\dfrac{1}{2}:\dfrac{3}{4}+\dfrac{1}{6}:\dfrac{3}{4}=\dfrac{1}{2}\times\dfrac{4}{3}+\dfrac{1}{6}\times\dfrac{4}{3}=\dfrac{4}{3}\times\left(\dfrac{1}{2}+\dfrac{1}{6}\right)=\dfrac{4}{3}\times\dfrac{2}{3}=\dfrac{8}{9}\)
d) \(\dfrac{1}{2}:\dfrac{3}{4}-\dfrac{1}{6}:\dfrac{3}{4}=\dfrac{1}{2}\times\dfrac{4}{3}-\dfrac{1}{6}\times\dfrac{4}{3}=\dfrac{4}{3}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)=\dfrac{4}{3}\times\dfrac{1}{3}=\dfrac{4}{9}\)
c)\(\dfrac{1}{2}:\dfrac{3}{4}+\dfrac{1}{6}:\dfrac{3}{4}=\dfrac{1}{2}.\dfrac{4}{3}+\dfrac{1}{6}.\dfrac{4}{3}=\left(\dfrac{1}{2}+\dfrac{1}{6}\right).\dfrac{4}{3}=\dfrac{2}{3}.\dfrac{4}{3}=\dfrac{8}{9}\)
d)\(\dfrac{1}{2}:\dfrac{3}{4}-\dfrac{1}{6}:\dfrac{3}{4}=\dfrac{1}{2}.\dfrac{4}{3}-\dfrac{1}{6}.\dfrac{4}{3}=\left(\dfrac{1}{2}-\dfrac{1}{6}\right).\dfrac{4}{3}=\dfrac{1}{3}.\dfrac{4}{3}=\dfrac{4}{9}\)
Tìm x
a) x : 1/4 = 7/5
b) 9/2 - x = 3/5
c) 12/5 : x = 7/2
nhanh giúp milk với sau 15 phút bạn nào nhanh nhất milk sẽ tick đúng
a) x : 1/4 = 7/5
x = 7/5 x 1/4
x = 7/20
b) 9/2 - x = 3/5
x = 9/2 - 3/5
x = 39/10
c) 12/5 : x = 7/2
x = 12/5 : 7/2
x = 24/35
a) \(x\div\dfrac{1}{4}=\dfrac{7}{5}\)
\(x=\dfrac{7}{5}\times\dfrac{1}{4}\)
\(x=\dfrac{7}{20}\)
b) \(\dfrac{9}{2}-x=\dfrac{3}{5}\)
\(x=\dfrac{9}{2}-\dfrac{3}{5}\)
\(x=\dfrac{39}{10}\)
c) \(\dfrac{12}{5}\div x=\dfrac{7}{2}\)
\(x=\dfrac{12}{5}\div\dfrac{7}{2}\)
\(x=\dfrac{12}{5}\times\dfrac{2}{7}\)
\(x=\dfrac{24}{35}\)
a)\(x=\dfrac{1}{4}\)x\(\dfrac{7}{5}=\dfrac{7}{20}\)
b)\(x=\dfrac{9}{2}-\dfrac{3}{5}=\dfrac{39}{10}\)
c)\(x=\dfrac{12}{5}:\dfrac{7}{2}=\dfrac{24}{35}\)
a) A= | x- 4,1| + | x - 2/3 | - 9
b) B=| 2 và 1/5 - x| + | x - 1/5 | + 8 và 1/5
c) C=| x + 3 và 1/2| + |x| - 3 và 1/2
tìm x
1/2 - (x- 1/4 ) = 1/3
3/2 * ( x- 1/2 -1 = 5/4
11/2 -9/2 * ( x- 3/4 ) = 1
làm nhanh mình đg cần gấp mk hứa ai làm nhanh mk tick
OK
1. 1/2-(x-1/4)=1/3
=> x-1/4=1/2-1/3
=> x-1/4= 1/6
=> x= 1/6+1/4=5/12
2. 3/2*(x-1/2-1)=5/4
=> x-1/2-1=5/4:3/2
=> x-1/2= 5/6+1
=> x = 11/6+1/2
=> x= 7/3
3. 11/2-9/2*(x-3/4)=1
=> 9/2*(x-3/4)= 11/2-1
=> x-3/4 = 9/2:9/2
=> x= 1+3/4
=> x= 7/4
Chúc bạn Hk tốt!!!!!
1. x=\(\frac{5}{12}\)
2. x=\(\frac{7}{3}\)
3. x= \(\frac{7}{4}\)
Chúc bạn Hk tốt!!!
Tìm giá trị nhỏ nhất
a) x2 + x + 1
b)4x2+4x-5
c)(x-3)(x+5) + 4
d)x2 - 4x + y2 - 8y + 6
a) x2 +x +1 = x2 + x + 1/4 + 3/4 =(x+1/2)2 + 3/4
=> GTNN a) =3/4 khi x=-1/2
b) 4x2 +4x -5 = 4x2 + 4x +1 -6 = (2x+1)2-6
=> GTNN b) = -6 khi x=-1/2
c) (x-3)(x+5) +4 = x2+2x -11 = x2+2x +1-12=(x+1)2-12
GTNN c) =12 khi x=-1
d) x2-4x+y2-8y+6=x2-4x+4+y2-8y+16-14=(x-2)2+(y-4)2-14
GTNN d) =-14 khi x=2 , y=4
\(a,=\left(x^2+x+\dfrac{1}{4}\right)+\dfrac{3}{4}=\left(x+\dfrac{1}{2}\right)^2+\dfrac{3}{4}\ge\dfrac{3}{4}\)
Dấu \("="\Leftrightarrow x=-\dfrac{1}{2}\)
\(b,=\left(4x^2+4x+1\right)-6=\left(2x+1\right)^2-6\ge-6\)
Dấu \("="\Leftrightarrow x=-\dfrac{1}{2}\)
\(c,=x^2+2x-15+4=\left(x+1\right)^2-12\ge-12\)
Dấu \("="\Leftrightarrow x=-1\)
\(d,=\left(x^2-4x+4\right)+\left(y^2-8y+16\right)-14=\left(x-2\right)^2+\left(y-4\right)^2-14\ge-14\)
Dấu \("="\Leftrightarrow\left\{{}\begin{matrix}x=2\\y=4\end{matrix}\right.\)
Tìm X, biết:
A) X x 2/5 + 1/2 x X = 9
B) 1/9 : X + 3/9 : X =5/7
a: \(x\cdot\dfrac{2}{5}+\dfrac{1}{2}\cdot x=9\)
=>\(x\left(\dfrac{2}{5}+\dfrac{1}{2}\right)=9\)
=>\(x\cdot\dfrac{9}{10}=9\)
=>\(x=9:\dfrac{9}{10}=10\)
b: \(\dfrac{1}{9}:x+\dfrac{3}{9}:x=\dfrac{5}{7}\)
=>\(\left(\dfrac{1}{9}+\dfrac{3}{9}\right):x=\dfrac{5}{7}\)
=>\(\dfrac{4}{9}:x=\dfrac{5}{7}\)
=>\(x=\dfrac{4}{9}:\dfrac{5}{7}=\dfrac{4}{9}\cdot\dfrac{7}{5}=\dfrac{28}{45}\)
a: =>x+7/4=6:2/3=9
=>x=29/4
b: =>x:5/3=7/5
=>x=7/5*5/3=7/3
c:=>x+1/6=5/3
=>x=10/6-1/6=3/2
d: =>x+4/5=4/5+3/7+3/5
=>x=3/7+3/5=36/35
e: =>x/35=4/5-5/7=3/35
=>x=3
f: =>13/28+x=1/2
=>x=1/28
g: =>1/3-x=1/9
=>x=2/9