Theo bài ra , ta có :
\(\dfrac{x+5}{25}+1+\dfrac{x+6}{24}+1+\dfrac{x+7}{23}=0\)
\(\Leftrightarrow\dfrac{x+5+25}{25}+\dfrac{x+6+24}{24}+\dfrac{x+7+23}{23}=0\)
\(\Leftrightarrow\dfrac{x+30}{25}+\dfrac{x+30}{24}+\dfrac{x+30}{23}=0\)
\(\Leftrightarrow\left(x+30\right)\left(\dfrac{1}{25}+\dfrac{1}{24}+\dfrac{1}{23}\right)=0\)
Vì \(\dfrac{1}{25}+\dfrac{1}{24}+\dfrac{1}{23}\ne0\)
\(\Leftrightarrow x+30=0\)
\(\Leftrightarrow x=-30\)
Vậy S={-30}
Chúc bạn học tốt =))
Ta có :
\(\dfrac{x+5}{25}+\dfrac{x+6}{24}+\dfrac{x+7}{23}=-3\)
=> \(\left(x+5\right).\dfrac{1}{25}+\left(x+5+1\right).\dfrac{1}{24}+\left(x+5+2\right).\dfrac{1}{23}=-3\)
=>\(\left(x+5\right).\dfrac{1}{25}+\left(x+5\right).\dfrac{1}{24}+\dfrac{1}{24}+\left(x+5\right).\dfrac{1}{23}+2.\dfrac{1}{23}\)= -3
=> (x + 5).\(\left(\dfrac{1}{25}+\dfrac{1}{24}+\dfrac{1}{23}\right)\) + \(\dfrac{1}{24}+\dfrac{2}{23}\) = -3
=> (x + 5). \(\dfrac{1727}{13800}\) + \(\dfrac{71}{552}\) = -3
=> (x + 5). \(\dfrac{1727}{13800}\) = -3 - \(\dfrac{71}{552}\)
=> (x + 5). \(\dfrac{1727}{13800}\) = \(\dfrac{-1727}{552}\)
=> x + 5 = -25
=> x = -25-5
=> x = -30
Vậy x = -30
Ta có:
\(\dfrac{x+5}{25}+\dfrac{x+6}{24}+\dfrac{x+7}{23}=-3\)
\(\Rightarrow\dfrac{x+5}{25}+1+\dfrac{x+6}{24}+1+\dfrac{x+7}{23}+1=0\)
\(\Rightarrow\dfrac{x+30}{25}+\dfrac{x+30}{24}+\dfrac{x+30}{23}=0\)
\(\Rightarrow\left(x+30\right)\left(\dfrac{1}{25}+\dfrac{1}{24}+\dfrac{1}{23}\right)=0\)
\(\Rightarrow x+30=0\)
\(\Rightarrow x=-30\)
Vậy x=-30
