Multiplying a number by 6 is equal to the number increased by 9. The phrase a number means an arbitrary variable, let's call it x. Multiply it by 6 --> 6x We set this equal to the same number increased by 9. Increased by means we add: 6x = x + 9 <-- This is our algebraic expression To solve this equation, we type it into the search engine and get x = 1.8.