x/15+7/20=73/60 11/8+13/6=85/x -7/x+8/15=-1/20 tìm x

2 bình luận về “x/15+7/20=73/60 11/8+13/6=85/x -7/x+8/15=-1/20 tìm x”

1. x/15+7/20=73/60

   (4x)/60+21/60=73/60

   => 4x+21=73

            4x=73-21

            4x=52

              x=52:4

              x=13

     Vậy x=13

   _______________________________

   11/8+13/6=85/x

   33/24+52/24=85/x

           85/24=85/x

   => x=24

   Vậy x=24

   ________________________________

   (-7)/x+8/15=(-1)/20

             (-7)/x=(-1)/20-8/15

             (-7)/x=(-3)/60-32/60

             (-7)/x=(-35)/60

          (-35)/(5x)=(-35)/60

    => 5x=60

              x=60:5

              x=12

   Vậy x=12

   $\color{red}{\text{@Hy~Hoctotnha}}$

            

   Trả lời
2. $\text{a, $\dfrac{x}{15}$ + $\dfrac{7}{20}$=$\dfrac{73}{60}$ }$

   $\text{ => $\dfrac{x}{15}$ = $\dfrac{73}{60}$ – $\dfrac{7}{20}$}$

   $\text{ => $\dfrac{x}{15}$ = $\dfrac{13}{15}$ }$

   $\text{ => x = 13 }$

   $\text{ Vậy x = 13 }$

   $\text{ b, $\dfrac{11}{8}$ + $\dfrac{13}{6}$ = $\dfrac{85}{x}$ }$

   $\text{ => $\dfrac{85}{24}$ = $\dfrac{85}{x}$ }$

   $\text{ => x = 24 }$
   $\text{ Vậy x = 24 }$

   $\text{c, $\dfrac{-7}{x}$ + $\dfrac{8}{15}$ = $\dfrac{-1}{20}$}$

   $\text{ => $\dfrac{-7}{x}$ = $\dfrac{-1}{20}$ – $\dfrac{8}{15}$ }$

   $\text{ => $\dfrac{-7}{x}$ = $\dfrac{-7}{12}$ }$
   $\text{ => x = 12 }$

   $\text{ Vậy x = 12 }$
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