Solve each system for x and y, expressing either value in terms of a or b, if necessary. Assume that a ≠ 0 and b ≠ 0. For the linear function f(x) = mx + b, f(−2) = 11 and ƒ(3) = -9. Find m and b.
Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
2. Graphs of Equations
Lines
Problem 7
Textbook Question
Use the given conditions to write an equation for each line in point-slope form and slope-intercept form. Passing through (2, −3) and perpendicular to the line whose equation is y = (1/5)x + 6
Verified step by step guidance1
Identify the slope of the given line from its equation \(y = \frac{1}{5}x + 6\). The slope is the coefficient of \(x\), which is \(\frac{1}{5}\).
Determine the slope of the line perpendicular to the given line. Recall that perpendicular slopes are negative reciprocals, so the new slope will be \(-5\) (since \(-\frac{1}{\frac{1}{5}} = -5\)).
Use the point-slope form of a line equation, which is \(y - y_1 = m(x - x_1)\), where \(m\) is the slope and \((x_1, y_1)\) is the given point. Substitute \(m = -5\) and the point \((2, -3)\) to get \(y - (-3) = -5(x - 2)\).
Simplify the point-slope form equation to \(y + 3 = -5(x - 2)\), which is the required point-slope form of the line.
Convert the point-slope form to slope-intercept form by distributing and isolating \(y\): \(y + 3 = -5x + 10\), then subtract 3 from both sides to get \(y = -5x + 7\).
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
3mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Point-Slope Form of a Line
The point-slope form is an equation of a line expressed as y - y₁ = m(x - x₁), where (x₁, y₁) is a point on the line and m is the slope. It is useful for writing the equation when a point and slope are known.
Recommended video:
Guided course
Point-Slope Form
Slope-Intercept Form of a Line
The slope-intercept form is y = mx + b, where m is the slope and b is the y-intercept. This form clearly shows the slope and where the line crosses the y-axis, making it easy to graph and interpret.
Recommended video:
Guided course
Graphing Lines in Slope-Intercept Form
Perpendicular Slopes
Two lines are perpendicular if their slopes are negative reciprocals, meaning m₁ * m₂ = -1. Given a slope m, the slope of a perpendicular line is -1/m, which helps find the slope of the required line.
Recommended video:
Guided course
Parallel & Perpendicular Lines
Related Videos
Related Practice
Textbook Question
82
views
1
rank
