Question 460110
3x^2 + 4y^2 - ( 5x^2 - 7y^2 - 1)



3x^2 + 4y^2 - 5x^2 + 7y^2 + 1



(3x^2 - 5x^2) + (4y^2  + 7y^2) + 1



-2x^2 + 11y^2 + 1



So 3x^2 + 4y^2 - ( 5x^2 - 7y^2 - 1) = -2x^2 + 11y^2 + 1