Question

Rút gọn:
a, (2x-1)^2 -2(2x-1)(x+3)+(x+3)^2
b, (4x+3)^2-2x(x+6)-5(x-2)(x+2)-10
c,(3x+1)(9x^2-3x+1)-((x-2)(x^2+2x+4)
d, (2x-1)^3-4x^2(2x-3)

Answer 1

\(a.\left(2x-1\right)^2-2\left(2x-1\right)\left(x+3\right)+\left(x+3\right)^2\)

\(=4x^2-4x+1-4x^2-10x+6+x^2+6x+9\)

\(=x^2-8x+16.\)

\(b.\left(4x+3\right)^2-2x\left(x+6\right)-5\left(x-2\right)\left(x+2\right)-10\)

\(=16x^2+24x+9-2x^2-12x-5x^2+20-10\)

\(=9x^2+12x+19.\)

\(c.\left(3x+1\right)\left(9x^2-3x+1\right)-\left(x-2\right)\left(x^2+2x+4\right)\)

\(=27x^3+1-x^3+8=26x^3+9.\)

\(d.\left(2x-1\right)^3-4x^2\left(2x-3\right)\)

\(=8x^3-12x^2+6x-1-8x^2+12x^2=6x-1.\)