Đáp án:
$c) 4x^2-2x^2y+11y^3-\frac{34}{3}x^3-9xy^2\\
d)
-x^3+6x^2-2y^3+5x\\
e) 8x^2y-10xy+16y^3$
Giải thích các bước giải:
$c) (4x^2+x^2y-5y^3)-\left ( \frac{5}{3}x^3-6xy^2-x^2y \right )+\left ( \frac{x^3}{3}+10y^3 \right )+(6y^3-15xy^2-4x^2y-10x^3)$
$=4x^2+x^2y-5y^3-\frac{5}{3}x^3+6xy^2+x^2y + \frac{x^3}{3}+10y^3 +6y^3-15xy^2-4x^2y-10x^3$
$=4x^2+(x^2y+x^2y-4x^2y)+(-5y^3+10y^3+6y^3)+(-\frac{5}{3}x^3+\frac{x^3}{3}-10x^3)+(6xy^2-15xy^2)\\
=4x^2-2x^2y+11y^3-\frac{34}{3}x^3-9xy^2\\$
d)
$(x^3+6x^2+5y^3)-(2x^3-5x+7y^3)\\
=x^3+6x^2+5y^3-2x^3+5x-7y^3\\
=(x^3-2x^3)+6x^2+(5y^3-7y^3)+5x\\
=-x^3+6x^2-2y^3+5x\\
e) (5,7x^2y-3,1xy+8y^3)-(6,9xy-2,3x^2y-8y^3)\\
=5,7x^2y-3,1xy+8y^3-6,9xy+2,3x^2y+8y^3\\
=(5,7x^2y+2,3x^2y)+(-3,1xy-6,9xy)+(8y^3+8y^3)\\
=8x^2y-10xy+16y^3$
