`text{Đáp án + Giải thích các bước giải}`
`text{Ta có:}`
$\sqrt{289}-5.\left|\dfrac{6}{25}:\sqrt x-\sqrt{49}\right|=-15\\\Rightarrow 17-5.\left|\dfrac{6}{25}:\sqrt x-7\right|=-15\\\Rightarrow 5.\left|\dfrac{6}{25}:\sqrt x-7\right|=32\\\Rightarrow\left|\dfrac{6}{25}:\sqrt x-7\right|=\dfrac{32}{5}$
`TH_1:`
`6/25: sqrtx -7=32/5`
`=>x=36/112225`
`TH_2`
`6/25:sqrtx-7=-32/5`
`=>x=36/225`
Vậy `x \in {36/225 , 36/112225}`
