find the missing value
(?) (10y^2 - 5y) = -40y^4 + 20y^3
The missing value is -4y.
-4y(10y^2 - 5y) = -40y^4 + 20y^3
Multiplying -4y by 10y^2 and -4y by -5y, we get:
-40y^3 + 20y^2 = -40y^4 + 20y^3
(?) (10y^2 - 5y) = -40y^4 + 20y^3
-4y(10y^2 - 5y) = -40y^4 + 20y^3
Multiplying -4y by 10y^2 and -4y by -5y, we get:
-40y^3 + 20y^2 = -40y^4 + 20y^3