\(\left(x+0.3\right)+\left(x+0.7\right)+......+\left(x+4.7\right)+\left(x+5.1\right)=48.1\)

\(x+0.3+x+0.7+......+x+4.7+x+5.1=48.1\)

\(\left(x+x+......+x\right)+\left(0.3+0.7+......+5.1\right)=48.1\)( 13 số x )

\(13x+35.1=48.1\)

\(13x=48.1-35.1=13\)

\(x=13:13=1\)

( x + 0.3 ) + ( x + 0.7 ) + ... + ( x + 5.1 ) = 48.1

( x + x + ... + x ) + ( 0.3 + 0.7 + .... + 5.1 ) = 48.1 ( có 13 số x )

13x + 35.1 = 48.1

13x = 13

x = 13 : 13 = 1

Giải:

\(A=\left|2,5-x\right|+\left(4,7+1,1\right)\)

\(\Leftrightarrow A=\left|2,5-x\right|+5,8\)

Vì \(\left|2,5-x\right|\ge0;\forall x\)

\(\Leftrightarrow\left|2,5-x\right|+5,8\ge5,8;\forall x\)

\(\Leftrightarrow A\ge5,8;\forall x\)

\(\Leftrightarrow A_{Min}=5,8\)

Dấu "=" xảy ra:

\(\Leftrightarrow2,5-x=0\Leftrightarrow x=2,5\)

Vậy ...

vậy... là sao

\(\frac{9x-0,7}{4}-\frac{5x-1,5}{7}=\frac{7x-1,1}{6}-\frac{5\left(0,4-2x\right)}{6}\)

\(\Leftrightarrow\frac{\left(9x-0,7\right)\cdot7}{4\cdot7}-\frac{\left(5x-1,5\right)\cdot4}{7\cdot4}=\frac{7x-1,1-2+10x}{6}\)

\(\Leftrightarrow\frac{63x-4,9-20x+6}{28}=\frac{7x-1,1-2+10x}{6}\)

\(\Leftrightarrow\left(63x-4,9-20x+6\right)\cdot6=28\left(7x-1,1-2+10x\right)\)

\(\Leftrightarrow378x-120x+6,6=196x-86,8+280x\)

\(\Leftrightarrow378x-120x-196x-280x=-86,8-6,6\)

\(\Leftrightarrow-218x=-93,4\)

\(\Leftrightarrow x=\frac{467}{1090}\)

Anh gì ơi anh viết xấu em ko nhìn thấy

x là 1,6

0.7 / x = 0.75 - 0.5 / x

0.75 = 0.5/x + 0.7/x

0.75 = (0.5+0.7)/x

0.75 = 1.2/x

x = 1.2/0.75

x = 1,6

\(-\dfrac{8}{11}.x=\dfrac{2}{5}.\dfrac{1}{4}\)

\(-\dfrac{8}{11}.x=\dfrac{2}{20}\)

\(-\dfrac{8}{11}.x=\dfrac{1}{10}\)

\(x=\dfrac{1}{10}:-\dfrac{8}{11}\)

\(x=-\dfrac{11}{81}\)

Chọn d

cảm ơn nha'