Multiply and simplify x 13 middot x 15 x3 1x5 1 x8 1 x1
     Multiply and simplify (x + 1)^3 middot (x + 1)^5.  (x^3 + 1)(x^5 + 1)  x^8 + 1  x^15 + 1  x^8 + x^5 + x^3 + 1  (x + 1)^8 
  
  Solution
12. We know that am*an = am+n. In this identity, if we replace a by (x+1), m by 3 and n by 5, we get (x+1)3. (x+1)5 = (x+1)3+5 = (x+1)8. The last option is the correct answer.
13. x5 = x2.x3

