164k views
1 vote
PLEASE HELP Directions: Use the information below to answer the questions below. Type or write your responses to questions 1-2 and upload your responses. Do your BEST! 1. Lisa is working with the system of equations x+2y=7 and 2x−5y=5. She multiplies the first equation by 2 and then subtracts the second equation to find 9y=9, telling her that y=1. Lisa then finds that x=5. Thinking about this procedure, Lisa wonders: There are lots of ways I could go about solving this problem. I could add 5 times the first equation and twice the second or I could multiply the first equation by -2 and add the second. I seem to find that there is only one solution to the two equations but I wonder if I will get the same solution if I use a different method? A. What is the answer to Lisa's question? Explain. B. Does the answer to (a) change if we have a system of two equations in two unknowns with no solutions? What if there are infinitely many solutions? 2. Graph (Links to an external site.) the following linear system. What is the solution? y = 2x + 4 y = 3x + 2

User VikasGoyal
by
4.3k points

1 Answer

7 votes

Answer:

PART 1:

A

Yes, Lisa will get the same solution no matter what method she applies. The reason is that we have been given 2 equations. As these are linear equations, both of the equations represent 2 different lines having different slopes. The solution of two different lines is taken as the point of intersection of both lines, because that is the only point that lies on both lines. This point will always remain the same for two particular lines. So whatever method Lisa applies, the point of intersection will always remain the same i.e (5,1)

B

Yes, the answer to A will change if the systems of equation has no solution. If system of equations have no solution, it means the both lines never intersect, which happens for parallel line. Hence, there is no point of intersection.

Yes, the answer to A will change if the systems of equation has infinite many solution. It means that both lines intersect at every point of each line, which happens when both lines overlap each other. Hence, the point of intersection, which represents the solution, is every point of both lines.

PART 2:

The graph of both equations is given below.

The solution is the point of intersection of both line

As both lines intersect a x = 2 and y = 8.

Solution: (2,8)

PLEASE HELP Directions: Use the information below to answer the questions below. Type-example-1
User WantTheBest
by
4.6k points