Question

Lines AB and CD (if present in the picture) are straight lines. Find x. Give reasons to justify your solutions.

Answer 1

WORDS: The value of x is 15.

EQUATION: x = 15

Explanation:

1. AB is a straight line therefore angles AOF, FOG, and GOB total 180º

2. If ∠FOG = 90º, AOF + GOB = 90º by subtraction & substitution property

3. 5x - 15 + 2x = 90 (now solve) --> by substitution

4. 7x - 15 = 90 --> by C.L.T. or Combine Like Terms

5. 7x = 105 --> by C.L.T. or Combine Like Terms

6. x = 15 --> by inverse operations (division)

Hope this helps!