1. How to set up Algebraic Equations to Match Real World Problems!

3. How to convert words to equations…
Problem.  Helen has 2 inches of hair cut off each time she goes to the hair salon. If h equals the length of hair before she cuts it and c equals the length of hair after she cuts it, which equation would you use to find the length of Helen's hair after she visit the hair salon? B
a. h = 2 − c      c. c = h − 2 b. c = 2 − h      d. h = c − 2

4. How to convert words to equations…
Problem.  Helen has 2 inches of hair cut off each time she goes to the hair salon. If h equals the length of hair before she cuts it and c equals the length of hair after she cuts it, which equation would you use to find the length of Helen's hair after she visit the hair salon? B E
1. Rewrite the question in words
2. Set it equal to…
3. The rest of the boxed-in words
length of Helen’s hair after cut =
length of hair before cut – cut off hair

5. How to convert words to equations…
Problem.  Helen has 2 inches of hair cut off each time she goes to the hair salon. If h equals the length of hair before she cuts it and c equals the length of hair after she cuts it, which equation would you use to find the length of Helen's hair after she visit the hair salon? B E
length of Helen’s hair after cut = S
length of hair before cut – cut off hair
substitute the c, h, and 2 into the relationships above, and then match with the equations (a) through (d).
C = h - 2
a. h = 2 − c      c. c = h − 2 b. c = 2 − h      d. h = c − 2

6. How did we know to subtract??
C = h - 2

8. Notes
Problem: Jeanne has $17 in her piggy bank. How much money does she need to buy a game that costs $68?
Hint: Let the variable represent what you are looking for…
IOW: What you underline in the CUBES method!
Solution: Let x represent the amount of money Jeanne needs. Then the following equation can represent this problem:
Variable
Algebraic Expression
17 + x = 68
We can subtract 17 from both sides of the equation to find the value of x.
68 – 17 = x
51 = x

9. Example 1:

10. Example 2:

11. Example 3: