Linear Equations

1. SOLVING PROBLEMS
INVOLVING LINEAR
EQUATIONS

2. EXAMPLE # 1: NUMBER PROBLEM
•Find five consecutive odd
integers whose sum is 55.

3. SOLUTION:
• Let x – be the first odd integer
• x + 2 – be the 2nd odd integer
• x + 4 – be the 3rd odd integer
• x + 6 – be the 4th odd integer
• x + 8 – be the 5th odd integer

4. •x + (x + 2) + (x + 4) + (x + 6) + (x + 8) = 55
•5x + 20 = 55
•5x + 20 + (– 20) = 55 – 20
•5x = 35
•x = 7

5. EXAMPLE #2: AGE PROBLEM
•Margie is 3 times older than Lilet.
In 15 years, the sum of their ages
is 38 years. Find their present
ages.

6. Age now In 15 years
Lilet x x + 15
Margie 3x 3x + 15

7. In 15 years, the sum of their ages is 38 years.
Equation: (x + 15) + (3x + 15) = 38
Solution: 4x + 30 = 38
4x = 38 – 30
4x = 8
x = 2
Answer: Lilet’s age now is 2 while, Margie’s age now is 3(2) or 6.