Question

(x+3)(x+5)(x+7)=? how to do it?

Answer 1

first solve first two brackets
then the remaining two

Answer 2

Given Equation is (x + 3)(x + 5)(x + 7)   --------- (1)

(1) (x + 3)(x + 5)

   = x * x + x * 5 + 3 * x + 3 * 5

  = x^2 + 5x + 3x + 15

  = x^2 + 8x + 15  -------------- (2)


Substitute (2) in (1), we get

Therefore (x+3)(x+5)(x+7) = (x^2 + 8x + 15)(x + 7)

                                          = x^2 * x + x^2 * 7 + 8x * x + 8x * 7 + 15 * x + 15 * 7

                                          = x^3 + 7x^2 + 8x^2 + 56x + 15x + 105

                                          = x^3 + 15x^2 + 7x + 105.


Hope this helps!