Question

simplify and verify:
(4a*2-6ab+9b*2)(2a+3b);a=2,b=1
answer please this question.

Answer 1

The required answer is 161
Hope it helps.

Answer 2

By multiplying we get

        8a^3 - 12 a^2b + 18 ab^2 + 12 a^2b - 18 ab^2 + 27 b^3

          8 a^3 + 27 b^3

         2a^3 + 3b^3

      This is in the form of

          a^3 + b^3 = (a +b)(a^2 -ab + b^2)

                          = (2a + 3b) (4a^2 - 6ab + 9b^2)

       Substituting a = 2, b = 1   we get

                          7 x 13 = 91