CPM Homework Help : CCG Problem 8-23

Multiple Choice: Which equation below is not a correct statement based on the information in the diagram?

$3x + y = 180°$

$2x-1°=4°-x$

$2x-1°=5y-10°$

$2x-1°+3x=180°$

Hint:

Read the Math Notes box in Lessons 2.1.1 and 2.1.4 about angle pair relationships.

Answer:

B because $2x-1º$ and $4º-x$ are a linear pair so $2x-1º+4°-x=180$ , not $2x-1º=4º-x$ .

Two intersecting sets of parallel lines. The upper left intersection has an exterior bottom angle, 4 degrees minus x, and an interior bottom angle, 2 x minus 1 degree. The upper, right intersection has an interior, top, angle, 5 y minus 10 degrees. The lower left intersection has an interior top angle, 3x, and the lower right intersection has an interior top angle, y.