Step-by-step explanation:
[tex]( {7x}^{2} - 4) - ( {3x}^{2} - 5x + 1)[/tex]
[tex] {7x}^{2} - 4 - {x}^{2} + 5x - 1[/tex]
[tex] {4x}^{2} + 5x - 5[/tex]
