(x-5)(x+7)-7x(x+3) (x+5)(x-7)-(x-4)(x+3) 20/09/2021 Bởi Eliza (x-5)(x+7)-7x(x+3) (x+5)(x-7)-(x-4)(x+3)
1. (x-5)(x+7)-7x(x+3) = $x^{2}$ +2x-35 – 7$x^{2}$ -21x = -6$x^{2}$ +-19x-35 2. (x+5)(x-7)-(x-4)(x+3) = $x^{2}$ -2x -35 -($x^{2}$-x-12) =-x-23 Bình luận
(x-5)(x+7)-7x(x+3) =x^2+7x-5x-35-7x^2-21x =-6x^2-19x (x+5)(x-7)-(x-4)(x+3) =x^2-7x+5x-35-(x^2+3x-4x-12) =x^2-7x+5x-35-x^2-3x+4x+12 =-x-23 Bình luận
1.
(x-5)(x+7)-7x(x+3)
= $x^{2}$ +2x-35 – 7$x^{2}$ -21x
= -6$x^{2}$ +-19x-35
2.
(x+5)(x-7)-(x-4)(x+3)
= $x^{2}$ -2x -35 -($x^{2}$-x-12)
=-x-23
(x-5)(x+7)-7x(x+3)
=x^2+7x-5x-35-7x^2-21x
=-6x^2-19x
(x+5)(x-7)-(x-4)(x+3)
=x^2-7x+5x-35-(x^2+3x-4x-12)
=x^2-7x+5x-35-x^2-3x+4x+12
=-x-23