Chapter 7.2, Problem 23E

To determine

To calculate: The product of the polynomial $(k+5)(k-1)$ using FOIL (Firsts Outsides Insides Lasts) method.

Answer to Problem 23E

The product of the polynomial $(k+5)(k-1)$ using FOIL method is $k^2+4k-5$

Explanation of Solution

Given information:

The given polynomial is $(k+5)(k-1)$ , where ‘k’ is a variable

Calculation:

On multiplying first term of both binomials,

  $k\times k=k^2$

On multiplying outside terms of each binomial,

  $k\times (-1)=-k$

On multiplying inside terms of both binomials,

  $5\times k=5k$

On multiplying last terms of each binomial,

  $5\times (-1)=-5$

On adding all these terms,

  $(k+5)(k-1)$ $=k^2-k+5k-5$

  $=k^2+4k-5$

Thus, the required product of the given polynomial is $k^2+4k-5$