\(A=6x^2-2x-6x^2-6x+3+8x\)
\(A=\left(6x^2-6x^2\right)+\left(-2x-6x+8x\right)+3\)
\(A=3\)
A = 2x.(3x – 1) – 6x.(x + 1) – (3 – 8x)
A = 2x.3x – 2x.1 – 6x.x – 6x.1 – 3 + 8x
A = 6^2 – 2x – 6^2 – 6x – 3 + 8x
A = -3
Sai đệ không chịu trách nhiệm đâu nha sư huynh :)))
Ta có: 2x(3x − 1) − 6x(x + 1) + (3 + 8x)
= 6x^2 - 2x - 6x^2 - 6x + 3 + 8x
= (6x^2 - 6x^2) + (-2x - 6x + 8x) + 3
= 0 + 0 + 3 = 0