Answer:
Question 1) Option C: 2(2x+1) = y, y = 2x + 8.
Question 4) Option C: y = x + 4, 2y = 2x + 8
Step-by-step explanation:
<h2>Definitions:</h2><h3><u><em>Perpendicular Lines</em></u></h3>
The graph of perpendicular lines will show an intersection of two lines at a single point, forming 90° adjacent angles. Since perpendicular lines intersect <u><em>at exactly one point</em></u>, then it means that they will have one solution. Additionally, perpendicular lines have <u><em>negative reciprocal slopes</em></u> for which multiplying the slopes of both lines result in a product of -1.
<h3><u><em>Coinciding Lines</em></u></h3>
Lines that have the same slope and y-intercept. Therefore, they are equivalent equations that will result in an infinitely many solutions. The graph of these lines will coincide on top of each other, as if they are the same line. The systems of linear equations that result in an infinitely many solutions are dependent and consistent. They are <u>dependent</u> if they have an infinite number of solutions, and <u>consistent</u> because they have at least one solution.
<h3><u>
<em /></u></h3><h3><u>
<em>Parallel lines</em></u></h3>
<u>Parallel lines</u> have the same slope. A systems of linear equations whose graph involve parallel lines have no solution, as there is no point of intersection between those two lines. Therefore, parallel lines have no solution, making it an <u>inconsistent</u> system.
<h2>Question 1:</h2>
We must transform these equations in its slope-intercept form, y = mx + b, which will allow us to easily determine the type of lines a given system has based on their slopes.
<h3>Option A:</h3>
<u>Equation 1</u>: 2x + y = 10
<u>Equation 2</u>: y = −2x + 8
Transform Equation 1 to slope-intercept form:
2x + y = 10
Subtract 2x from both sides:
2x - 2x + y = - 2x + 10
y = -2x + 10 ⇒ This is the slope-intercept form of Equation 1.
Since Equations 1 and 2 have the same slope, but different y-intercepts, then it means that they are <u>parallel lines</u> that have no point of intersection.
<h3>Option B:</h3>
Transform both equations to slope-intercept form:
<u>Equation 1</u>: 2x + 4y = 10
⇒ This is the slope-intercept form of Equation 1.
<u>Equation 2</u>: 2(x+2y) = 10
Distribute 2 into the parenthesis:
2(x+2y) = 10
2x + 4y = 10 ⇒ It is clear at this point that this equation matches Equation 1. Thus, the slope-intercept form of Equation 2 will be the same:
⇒ Slope-intercept form of Equation 2.
It turns out that Equations 1 and 2 are equivalent, as they have exactly the same slope and y-intercept. Therefore, they have <u>coinciding lines</u> and have <u><em>infinitely many solutions</em></u>.
<h3>Option C:</h3>
Transform both equations to slope-intercept form:
<u>Equation 1</u>: 2(2x+1) = y
y = 4x + 2 ⇒ Slope-intercept form of Equation 1.
<u>Equation 2</u>: y = 2x + 8
<h3>Option D:</h3>
<u>Equation 1</u>: y = 10 − 2x
y = − 2x + 10 ⇒ This is the slope-intercept form of Equation 1.
<u>Equation 2</u>: y = −2x + 7
Since Equations 1 and 2 have the same slope, but different y-intercept, then it means that they are <u><em>parallel</em></u> from each other.
<h3><u /></h3><h3><u>Answer for Question 1:</u></h3>
Out of all the given four options, Option C seems to be the correct answer, since the given system has varying slopes and y-intercept. Therefore, the correct answer for <u>Question 1</u> is <em><u>Option C:</u></em> 2(2x+1) = y, y = 2x + 8.
<h2>Question 4:</h2>
For Question 4, I will not elaborate as thoroughly as in Question 1 since I'll be using the same techniques.
<h3>Option A)</h3>
<u>Equation 1:</u> 2x+ 7x + y = 6
Combine like terms:
2x+ 7x + y = 6
9x + y = 6
Subtract 9x from both sides:
9x - 9x + y = - 9x + 6
y = - 9x + 6 ⇒ Slope-intercept form of Equation 1.
<u>Equation 2</u>: y = 9x + 6
Option A Explanation:
Equations 1 and 2 have different slopes and the same y-intercept. This implies that they will have a point of intersection = one solution. However, they don't have perpendicular lines because their slopes are not negative reciprocal of each other. Hence, Option A is not a valid answer for question 4.
<h3>Option B)</h3>
<u>Equation 1</u>: y = 5x + 7
<u>Equation 2</u>: y = 2x + 8
Option B explanation:
Similar to Option A, Equations 1 and 2 have different slopes and varying y-intercepts. Since they are not parallel from each other, and <u>do not have coinciding lines</u>, then Option B is not a valid answer for question 4.
<h3>Option C)</h3>
<u>Equation 1</u>: y = x + 4
<u>Equation 2</u>: 2y = 2x + 8
Transform Equation 2 to Slope-intercept form:
Divide both sides by 2 to isolate y:
y = x + 4 ⇒ This is the slope-intercept form of Equation 2.
<u>Option C explanation: </u>
Equations 1 and 2 are equivalent, as they have exactly the same slope and y-intercept. They also have <u>coinciding lines,</u> having <u><em>infinitely many solutions</em></u>.
<h3>Therefore,
Option C is the correct answer for Question 4. </h3>
<h3>Option D)</h3>
<u>Equation 1</u>: 7x − y = 10
y = 7x - 10 ⇒ This is the slope-intercept form of Equation 1.
<u>Equation 2</u>: y = 6x + 8
Option D explanation:
Similar to Option B, Equations 1 and 2 have different slopes and varying y-intercepts. Since they are not parallel from each other, and <u>do not have coinciding lines</u>, then Option D is not a valid answer for question 4.