( ?)(8y^2−4y^4)=40y^4−20y^6 find the missing term
The missing term is -10y^6.
When you multiply the two terms together, you get:
(8y^2) * (-4y^4) = -32y^6
Therefore, the complete expanded form is:
(8y^2−4y^4)=-32y^6 + 40y^4−20y^6 = 40y^4−52y^6.