HS AL2 L2 S1 02 11 UT Part 2 Student
Name: Courtney carlisle
Date:
Graded Assignment
Unit Test, Part 2: Linear Equations and Systems
Answer the questions below. When you have finished, submit this assignment to your teacher by the due date for full credit.
(10 points)
1. The table gives the population of a town for the years 2000–2009.
a. Make a scatter plot of the data, draw a line of best fit, and then find the equation of the line of best fit. Show and explain your work.
b. Describe what the slope of the line of best fit represents.
c. Use the equation to predict the population in the year 2013. Show your work.
Answer: line of best fit represents the average population increase per year over 10 years.
(2363 - 1065 )/ 10 years = 129.8/year 2013-2009 = 4 years
Pop. in 2009 + (4 years x 129.8/year) = 2363 + 519 = 2882
(10 points)
2. The manager of a fish store has water that is 10% salt and water that is 25% salt. He needs to fill an aquarium with 5 gallons of water that is 20% salt.
a. Write a system of linear equations that you can use to determine how many gallons of each type of salt water the manager should combine. Be sure to define your variables.
b. Solve the system and determine how many gallons of each type of salt water the manager should combine. Show all your work.
Answer:
Let quantity be mixed be x salt=10%=0.1x water=90%=0.9x
Let the quantity added be 5-xv salt=25%=0.25(5-x) water=75%=0.75(5-x)
Total salt =0.1x+0.25(5-x) which also should be equal to 20% of 5gallons = 0.2*5=1 0.1x+0.25(5-x)=1 0.1x+1.25-0.25x=1 1.25-0.15x=1 0.25=0.15x 25/15=x x=5/3=1.66gallons of Mixture A and rest of mixture B ie 5-1.66 ie 3.33gallons
Date:
Graded Assignment
Unit Test, Part 2: Linear Equations and Systems
Answer the questions below. When you have finished, submit this assignment to your teacher by the due date for full credit.
(10 points)
1. The table gives the population of a town for the years 2000–2009.
a. Make a scatter plot of the data, draw a line of best fit, and then find the equation of the line of best fit. Show and explain your work.
b. Describe what the slope of the line of best fit represents.
c. Use the equation to predict the population in the year 2013. Show your work.
Answer: line of best fit represents the average population increase per year over 10 years.
(2363 - 1065 )/ 10 years = 129.8/year 2013-2009 = 4 years
Pop. in 2009 + (4 years x 129.8/year) = 2363 + 519 = 2882
(10 points)
2. The manager of a fish store has water that is 10% salt and water that is 25% salt. He needs to fill an aquarium with 5 gallons of water that is 20% salt.
a. Write a system of linear equations that you can use to determine how many gallons of each type of salt water the manager should combine. Be sure to define your variables.
b. Solve the system and determine how many gallons of each type of salt water the manager should combine. Show all your work.
Answer:
Let quantity be mixed be x salt=10%=0.1x water=90%=0.9x
Let the quantity added be 5-xv salt=25%=0.25(5-x) water=75%=0.75(5-x)
Total salt =0.1x+0.25(5-x) which also should be equal to 20% of 5gallons = 0.2*5=1 0.1x+0.25(5-x)=1 0.1x+1.25-0.25x=1 1.25-0.15x=1 0.25=0.15x 25/15=x x=5/3=1.66gallons of Mixture A and rest of mixture B ie 5-1.66 ie 3.33gallons