suy ra3.(5x-1) - 4.(5x-1) + 6(5x-1) =15
suy ra 5.(5x-1) = 15
suy ra 5x-1=3
suy ra x=4/5
\(\Leftrightarrow3\left(5x-1\right)-4\left(5x-1\right)+6\left(5x-1\right)=15\)
\(\Leftrightarrow\left(3-4+6\right)\left(5x-1\right)=15\)
\(\Leftrightarrow5\left(5x-1\right)=15\)
\(\Leftrightarrow5x-1=\frac{15}{5}=3\)
\(\Leftrightarrow5x=3+1=4\)
\(\Leftrightarrow x=\frac{4}{5}\)
Vậy \(x=\frac{4}{5}\)
\(\sqrt{9\left(5x-1\right)}-\sqrt{16\left(5x-1\right)}+\sqrt{36\left(5x-1\right)}=15\)
<=> \(3\sqrt{5x-1}-4\sqrt{5x-1}+6\sqrt{5x-1}=15\)
<=> \(5\sqrt{5x-1}=15\)
<=> \(25\left(5x-1\right)=225\) (bình phương 2 vế)
<=> 5x - 1 = 225 : 25
<=> 5x - 1 = 9
<=> 5x = 9 + 1
<=> 5x = 10
<=> x = 2
\(\sqrt{9.\left(5x-1\right)}-\sqrt{16.\left(5x-1\right)}-\sqrt{36.\left(5x-1\right)}=15\)
\(< =>\sqrt{5x-1}.\left(3-4+6\right)=15\)
\(< =>5.\sqrt{5x-1}=15\)
Bình phương 2 vế lên ta có :
\(< =>25.\left(5x-1\right)=225\)
\(< =>5x-1=\frac{225}{25}=9\)
\(< =>5x=9+1=10\)
\(< =>x=\frac{10}{5}=2\)