Exponents        Single Var. Eq.        Multi-Var. Eq.    Word Problems        Factoring        Fractions        Ratios        Number Lines        Coordinate Plane       Square Roots        Scientific Not. Word problems (or story problems) usually strike fear into the hearts of young and old math students alike!  In all reality, they aren't that bad. To solve these problems, you look for statements in the problems that describe quantities that are equal.  Then, you use algebra to write an equation that can be solved.  It is customary to use variables that make it easier to remember what you're looking for, therefore, you don't use x or y in most cases. ``` 1. Problem: The sum of twice a number plus 13 is 75. Find the number. Solution: The word is means equals. The word and means plus. Therefore, you can rewrite the problem like the following: The sum of twice a number and 13 equals 75. Using numbers and a variable that represents something, N in this case (for number), you can write an equation that means the same thing as the original problem. 2N + 13 = 75 Solve this equation by isolating the variable. 2N + 13 = 75 Equation. - 13 = -13 Add (-13) to both sides. ------------- 2N = 62 N = 31 Divided both sides by 2. 2. Problem: Find a number which decreased by 18 is 5 times its opposite. Solution: Again, you look for words that describe equal quantities. Is means equals, and decreased by means minus. Also, opposite always means negative. Keeping that information in mind makes it so an equation can be written that describes the problem, just like the following: N - 18 = 5(-N) Equation. N - 18 = -5N Multiplied out. 5N + 18 5N + 18 Add (5N + 18) to ------------------ both sides. 6N = 18 N = 3 Divide both sides by 6 to isolate N.``` Take the Quiz on word problems.  (Very useful to review or to see if you've really got this topic down.)  Do it!

Math for Morons Like Us - Algebra: Word Problems
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