x+30%x=-1,31

x+0,3=-1,31

x=-1,31-0,3

x=-1,61

Thắng Mai bảo t k cho m

\(x+30\%x=-1,31\\ x+\dfrac{3}{10}x=-1\dfrac{31}{100}\\ x\cdot\left(1+\dfrac{3}{10}\right)=-\dfrac{131}{100}\\ x\cdot\dfrac{13}{10}=-\dfrac{131}{100}\\ x=-\dfrac{131}{100}:\dfrac{13}{10}=\dfrac{-131}{100}\cdot\dfrac{10}{13}=-\dfrac{131}{130}\)

x + 30%x = - 1,31

1,3 x = - 1,31

x = -131/130

131/130

k nha

       x + 30% x = -1,31

<=> x + 3/10 x = -32/31

<=>1x + 3/10 x=-32/31

<=> 10/10 x + 3/10 x = -32/31

<=> x . 13/10 = -32/31

=> x= -32/31 : 13/10=.....?

Ta có: x(1+30%)=-1,31

  ⇒        \(\dfrac{13}{10}\)x         =-1,31

  ⇒         x             =-1,31 : \(\dfrac{13}{10}\)

  ⇒         x             = -\(\dfrac{131}{130}\)

x + 30% x = -1,31

\(x+\dfrac{30}{100}x=-1,31\)

x+0,3x=-1,31

x.(0,3+1)=-1,31

x.1,3=-1,31

\(x=\dfrac{-1,31}{1,3}\)

\(x=-\dfrac{131}{130}\)

x+30%x=-1,31

<=> x(0.3+1)=-1,31

<=> X=\(\frac{-1,31}{1,3}\)

<=>x.(1+30%)=-1,31

<=>x.1,31=-1,31

<=>x=-1

\(x+30\%x=-1,31\)

\(\Leftrightarrow x+\dfrac{30}{100}x=-1,31\)

\(\Leftrightarrow\dfrac{13}{10}x=-1,31\)

\(\Leftrightarrow x=-\dfrac{131}{130}\)

Ta có: x + 30 % x = -131/100

          x ( 1 + 30%) = -131/100

          x 13/10=-131/100

          x = -131/100 ; 13/10

          x = -131/130

 b) )x+3/-15=1/3

x = 1/3 -3/-15

x= 8/15 

=> x = \(\frac{8}{15}\)

Ta có: x + 30 % x = -131/100

          x ( 1 + 30%) = -131/100

          x 13/10=-131/100

          x = -131/100 ; 13/10

          x = -131/130

Ta có: x + 30 % x = -131/100

          x ( 1 + 30%) = -131/100

          x 13/10=-131/100

          x = -131/100 ; 13/10

          x = -131/130

\(x+\dfrac{30}{100}.x=-1,31\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ x.\left(1+\dfrac{30}{100}\right)=\dfrac{-131}{100}\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ x.\left(\dfrac{100}{100}+\dfrac{30}{100}\right)=\dfrac{-131}{100}\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ x.\dfrac{26}{20}=\dfrac{-131}{100}\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\\\ \\ x=\dfrac{-131}{100}:\dfrac{26}{20}=\dfrac{-131}{100}.\dfrac{20}{26}\\ \\ \\ \\ \\ \\ \\ \\ \\\\ \\ x=\dfrac{-131}{130}\)

coi chừng mình làm sai nhưng trinh bày mình đúng nhưng cẩn thận kết quả. nhé bye

x+\(\dfrac{30}{100}\).x=-1,31

x+0,3.x=-1,31

x.(0,3+1)=-1,31

x.1,3=-1,31

x=-1,31:1,3

x=\(\dfrac{-131}{130}\)

Vậy x=\(\dfrac{-131}{130}\)

Chúc bạn học tốt nha

x+\(\dfrac{30}{100}\).x=-1,31

x.1+\(\dfrac{30}{100}\)x=\(\dfrac{-131}{100}\)

x(1+\(\dfrac{30}{100}\))=\(\dfrac{-131}{100}\)

x(\(\dfrac{100}{100}\)+\(\dfrac{30}{100}\))=\(\dfrac{-131}{100}\)

x.\(\dfrac{130}{100}\)=​​​\(\dfrac{-131}{100}\)​

x=\(\dfrac{-131}{100}\):\(\dfrac{130}{100}\)

x=\(\dfrac{130}{100}\).\(\dfrac{100}{131}\)

x=\(\dfrac{100.130}{131.100}\)

x=\(\dfrac{130.1}{131.1}\)

x=\(\dfrac{130}{131}\)

\(x+\frac{3}{10}x=-\frac{131}{100}\)

\(x.\left(1+\frac{3}{10}\right)=-\frac{131}{100}\)

\(x.\frac{13}{10}=-\frac{131}{100}\)

\(x=-\frac{131}{100}:\frac{13}{10}\)

\(x=-\frac{131}{130}\)