a,Tìm x biết: 5 x X / X – 13 = 49 x 0,5 – 7 x 0,5 + 0,25 16/09/2021 Bởi Kylie a,Tìm x biết: 5 x X / X – 13 = 49 x 0,5 – 7 x 0,5 + 0,25
$\text{$\dfrac{5×x}{x-13}$=49×0,5-7×0,5+0,25}$ $\text{⇒ $\dfrac{5×x}{x-13}$=0,5×42+0,25}$ $\text{⇒$\dfrac{5×x}{x-13}$=0,25×84+0,25}$ $\text{⇒$\dfrac{5×x}{x-13}$=0,25×85}$ $\text{⇒$\dfrac{5×x}{x-13}$=$\frac{85}{4}$}$ $\text{⇒$\left \{ {{5×x=85} \atop {x-13=4}} \right.$}$ $\text{⇒$\left \{ {{x=17} \atop {x=17}} \right.$}$ $\text{Vậy x=17}$ Bình luận
$\text{$\dfrac{5×x}{x-13}$=49×0,5-7×0,5+0,25}$
$\text{⇒ $\dfrac{5×x}{x-13}$=0,5×42+0,25}$
$\text{⇒$\dfrac{5×x}{x-13}$=0,25×84+0,25}$
$\text{⇒$\dfrac{5×x}{x-13}$=0,25×85}$
$\text{⇒$\dfrac{5×x}{x-13}$=$\frac{85}{4}$}$
$\text{⇒$\left \{ {{5×x=85} \atop {x-13=4}} \right.$}$
$\text{⇒$\left \{ {{x=17} \atop {x=17}} \right.$}$
$\text{Vậy x=17}$
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