Question

Lines A and CD (if shown) are straight lines. Find x. Give reasons to justify your solutions.
Please Write in a form like the table below.

Answer 1

Answer/Step-by-step explanation:

STATEMENT ====> REASONS

1. m<AOB = 180° ==> 1. Definition of straight angle

2. m<AOF + m<FOG + m<GOB = m<AOB ==> 2. Angle Addition Postulate

3. (5x - 15)° + 90° + 2x = 180° ==> 3. Substitution

4. Solve as algebra to get x

5x - 15 + 90 + 2x = 180

Collect like terms

5x + 2x - 15 + 90 = 180

7x + 75 = 180

Subtract 75 from both sides

7x + 75 - 75= 180 - 75

7x = 105

Divide both sides by 7

7x/7 = 105/7

x = 15 ===> 4. Algebra