\(\dfrac{12x^2+30x-21}{16x^2-9}-\dfrac{3x-7}{3-4x}=\dfrac{6x+5}{4x+3}\left(Đk:x\ne\pm\dfrac{3}{4}\right)\)
\(12x^2+30x-21+\left(3x-7\right)\left(4x+3\right)=\left(6x+5\right)\left(4x-3\right)\)
\(12x^2+30x-21+12x^2-19x-21=24x^2+2x-15\)
\(9x=27\)
\(x=3\)