[tex]6x {}^{2} - 5x + 3 - ( {3x}^{2} + 8x - 4)[/tex]
[tex] = 6 {x}^{2} - 5x + 3 - {3x}^{2} - 8x + 4[/tex]
[tex] = ( {6x}^{2} - {3x}^{2} ) + ( - 5x - 8x) + (3 + 4)[/tex]
[tex] = {3x}^{2} - 13x + 7[/tex]
