1/ Ta có: \(5x\left(x-3\right)=\left(x-2\right)\left(5x-1\right)-5\)
\(\Rightarrow5x^2-15x=5x^2-11x+2-5\)
\(\Rightarrow-15x=-11x-3\)
\(\Rightarrow-15x+11x=-3\)
\(\Rightarrow-4x=-3\Rightarrow x=\frac{3}{4}\).
2/ Ta có: \(\left(2x-1\right)\left(x-2\right)-\left(x+3\right)\left(2x-7\right)=3\)
\(\Rightarrow2x^2-5x+2-2x^2+x+21-3=0\)
\(\Rightarrow-4x+20=0\Rightarrow-4x=-20\Rightarrow x=5\).
Chúc bn hc tốt!
1/ \(5x\left(x-3\right)=\left(x-2\right)\left(5x-1\right)-5\)
<=> \(5x^2-15x=\left(5x^2-x-10x+2\right)-5\)
<=> \(5x^2-15x=5x^2-11x-3\)
<=> \(5x^2-15x-5x^2+11x+3=0\)
<=> \(-4x+3=0\)
<=> \(x=\frac{3}{4}\)
2/ \(\left(2x-1\right)\left(x-2\right)-\left(x+3\right)\left(2x-7\right)=3\)
<=> \(2x^2-4x-x+2-\left(2x^2-7x+6x-21\right)=3\)
<=> \(2x^2-5x+2-2x^2+x+21=3\)
<=> \(-4x+21=3\)
<=> \(4x=17\)
<=> \(x=\frac{17}{4}\)
