Question

(4u-4bn)(u+2bn) find the product

Answer 1

$(4u-4bn)(u+2bn)$ 

$4u^2+8ubn-4bnu-8b^2n^2$ 

$4u^2+(8bnu-4bnu)-8b^2n^2$ 

$4u^2+4bnu-8b^2n^2$