a: \(=2x^2+3x^2-3-5x^2-5x=-5x-3\)
b: \(=8x+16-5x^2-10x+4x^2-4x-8+2x^2-8+10\)
\(=x^2-6x+10\)
c: \(=4\left(x^2+4x-5\right)-\left(x^2+7x+10\right)-3\left(x^2+x-2\right)\)
\(=4x^2+16x-20-x^2-7x-10-3x^2-3x+6\)
\(=6x-24\)
a) 2x2 + 3(x - 1)(x + 1) - 5x(x + 1)
= 2x3 - 2x2 + 2x3 + 2x2 + 3x - 3 + 3x + 3 - 5x2 - 5x
= 2x2 + 3x2 - 3 - 5x2 - 5x
b) (8 - 5x)(x + 2) + 4(x - 2)(x + 1) + 2(x - 2)(x + 2) + 10
= 8x + 16 - 5x2 - 10x + 4x2 - 4x - 8 + 2x2 - 8 + 10
= x2 + 6x + 10
c) 4(x - 1)(x + 5) - (x + 2)(x + 5) - 3(x - 1)(x + 2)
= 4x - 4 + 4x + 20 - x2 + 5x + 2x + 10 - 3x + 3 - 3x - 6
= 6x - 24
d) mờ quá
