Question 242115
Hello.  This equation is taught in Pre-Algebra.  
.
In Algebraic equations we use a lot of variables.  These can be represented by any letter of the alphabet (although usually we see "x") and they mean an unknown numeric value.  The objective is to find the value or values of the variable.
.
When we see a letter next to a number, it means they multiply each other.  Although we would typically see the number first, then the letter (examples: 25k, 4x, 3y, etc).  The parenthesis are not always there when we deal with one number and one letter... but k(15) is not wrong, just uncommon.
.
Step:
a. isolate the variable by either adding,deducting, multiplying, or dividing both sides of the equation to determine the variable's value.
.
The problem:
{{{k(25)=165}}}
Since k and 25 are being multiplied, we are going to divide 25 from both sides to isolate k.
{{{(k(25))/25=(165/25)}}}
{{{k=165/25}}}
{{{k=11}}} <--- this is your solution.
.
I found this web site that explain things very clearly and shows many examples.  You might find it helpful.  Although you're more than welcomed to keep using Algebra.com to submit your problems.
.
This is the main page about Algebra.
http://www.mathsisfun.com/algebra/index.html
.
This is the intorduction to Algebra.  It shows you samples with variables and how to use them.
http://www.mathsisfun.com/algebra/introduction.html