- #1
Parsifal1
- 61
- 3
Homework Statement
Expand the brackets to get a cubic containing the unknowns. This is an example in the textbook but I don't see how they've expanded the brackets to get their answer:
(x-3)(px^2+qx+r)=px^3+(q-3p)x^2+(r-3q)x-3r
Homework Equations
(x-3)(px^2+qx+r)
The Attempt at a Solution
I would have done it how you expand long brackets:
(x-3)(px^2)+(x-3)(qx)+(x-3)(r)=px^3-3px^2...