Question

find the product of(a^2+2b^2)(5a-3b)​

Answer 1

(a²+2b²) (5a-3b)    

Expand (a²+2b²) using the identity (a²+b²) = a²+2ab+b²

(a²+4ab+4b²)(5a-3b)

Now take the second term as 1st term to make multiplication easy.

(5a-3b)(a²+4ab+4b²)

Now multiply

5a(a²+4ab+4b²)-3b(a²+4ab+4b²)

5a²+ 20a²b+20ab²-3a²b-12ab²-12b³

Cancel 20a²b and -3a²b, 20ab²-12 ab²

5a²+17a²b+8ab²-12b³

So the answer is 5a²+17a²b+8ab²-12b³.