Question

dùng hằngđẳng thức tính:

a) -(4-2y)³

b) -(a-2)³

help!!!!!!!!!!!!!!!!!

Answer 1

a) \(-\left(4-2y\right)^3\)

\(=-\left(64-96y+48y^2-8y^3\right)\)

\(=-64+96y-48y^2+8y^3\)

b) \(-\left(a-2\right)^3\)

\(=-\left(a^3-6a^2+12a-8\right)\)

\(=-a^3+6a^2-12a+8\)

Answer 2

\(-\left(4-2y\right)^3=-\left(64-96y+48y^2-8y^3\right)=-64+96y-48y^2+8y^3\)\(-\left(a-2\right)^3=-\left(a^3-6a^2+12a-8\right)=-a^3+6a^2-12a+8\)

Answer 3

a, \(-\left(4-2y\right)^3=-\left(4^3-3.16.2y+3.4.4y^2-8y^3\right)=-\left(64-96y+48y^2-8y^3\right)=-64+96y-48y^2+8y^3\)

b, \(-\left(a-2\right)^3=-\left(a^3-6a^2+12a-8\right)=-a^3+6a^2-12a+8\)