Đáp án+Giải thích các bước giải:
A=x(x-2)(x+2)-$(x+3)^2$
A=x($x^2$-4)-($x^2$+6x+9)
A=$x^3$-4x-$x^2$-6x-9
A=$x^3$+-$x^2$+10x-9
B=$x^2$($4y^2$-2x+10-4xy-4y)
B=$4x^2y^2$-$2x^3$+$10x^2$-$4x^3y$-$4x^2y$
C=(y-3)(y+3)($y^2$+9)-($y^2$+2)($y^2$-2)
C=($y^2$-9)($y^2$+9)-($y^2$+2)($y^2$-2)
C=$y^4$-81-$y^4$+4
C=-77