MCAS Strategy of the Week
Process of Elimination
Practice this strategy at home!
How do I use process of elimination to answer this question?
Use prior knowledge to eliminate incorrect answers - In Algebra 1, students learned that the slope of parallel lines, two lines that never intersect, is the same (memorize this!) Given this information, and knowing that perpendicular lines do intersect, you can eliminate option B! Cross it out on the test.
Now it gets tricky. How about drawing two perpendicular lines? Compare the slopes. One will increase, the other will decrease, that tells us that since the original line is negative (decreasing slope), the line that is perpendicular should be positive. Cross out option A!
Perpendicular slopes have the opposite reciprocal. Memorize this! Look at the drawing again - this makes sense! Eliminate option C and you're left with the correct answer - D.