Algebra and Up:
Question: There are two perpendicular lines graphed on a plane. Line A goes through the points (2,1) and (6, 3). Line B goes through (2, 1) and (x, 5). Solve for x.
Answer: x = 0
Solution:
To solve for x, we need to know the slope of Line B. Line A and Line B are perpendicular, so the slope of Line B is the opposite of the reciprocal of the slope of Line A. Line A’s slope is ½, so the slope of Line B must be –2. Now that we have a point on the line and its slope, we can write an equation in slope-intercept form:
y = –2x + b
y = 1 x = 2
1 = –4 + b
b = 5
y = –2x + 5
5 is the y–intercept. When y = 5, then x = 0.
Mathnasium of West Covina is a math-only learning center for K-12 students in West Covina, CA. Trusted by over a million parents, Mathnasium uses personalized learning plans and the proprietary Mathnasium Method™ to help students catch up, keep up, and get ahead on their math journey.
Our specially trained tutors deliver face-to-face instruction in a supportive and fun small-group environment, working with students to develop a deep understanding of math, build confidence, and improve academic performance.
Schedule Assessment
(626) 387-3639
(626) 387-3639
