1) A = (2x - 3) ² - (x - 3) ³ + (4x + 1) (16x ² - 4x +1) tại x = -2.
A=[2(-2) - 3] ² - [(-2) - 3] ³ + [4(-2) + 1][16(-2)² - 4(-2) +1)]
A=[-7]²-[-5]³+[-7][25]
A=49+125-175
A=-1
2) C = (x - 5y) ² + (2x - 3y) ³ - (x - y) ³ - (2x + 3y) (4x ² - 6xy + 9y ²) tại x=y= -$\frac{1}{2}$
C = [(-$\frac{1}{2}$) - 5(-$\frac{1}{2}$)]² + [2(-$\frac{1}{2}$) - 3(-$\frac{1}{2}$)] ³ - [(-$\frac{1}{2}$) - (-$\frac{1}{2}$)] ³ - [2(-$\frac{1}{2}$) + 3(-$\frac{1}{2}$)][4(-$\frac{1}{2}$) ² - 6(-$\frac{1}{2}$)(-$\frac{1}{2}$) + 9(-$\frac{1}{2}$) ²]
C = [2]² + [$\frac{1}{2}$]³- [(-$\frac{5}{2}$)][$\frac{7}{4}$]
C = 4+ $\frac{1}{8}$+$\frac{35}{8}$
C=$\frac{17}{2}$
3) E = (2x - y) (4x² + 2xy + y² ) - (3x + y) ³ + (x - 2y) ³ tại x = -1 ; y = 2.
E = [2(-1) - (2)][4(-1)² + 2(-1)(2) + (2)² ] - [3(-1) + (2)] ³ + [(-1) - 2(2)] ³
E = [-4][4] - [-1] ³ + [-5] ³
E=-16+1-125
E=-140