Download 2x + 3y = 15 8x + 7y = 2 5x – 3y = 6 8x + 3y = 10

Name: _________________
Algebra
Date:__________
Advisory:__________
Lesson 6-6: NOW YOU TRY:
A)
B)
2x + 3y = 15
5x – 3y = 6
8x + 7y = 2
8x + 3y = 10
C) Twice one number added to another number is 18. Four times the first number minus the
other number is 12. Find the numbers.
Let x represent the first number and y represent the other number.
Write two equations to represent the problem. Then solve the system using elimination.
Finished Early? Solve C using the substitution method to check your answer!
QUICK PRACTICE: Just start the following problems by adding or subtracting to eliminate
one of the variables. You do not need to solve!
1.
2.
2x – y = 1
4x + y = 11
4x + 7y = 26
4x – 5y = 2
Summarize: How do you know whether you should add or subtract when using the elimination
method?
INDEPENDENT PRACTICE: to be completed IN YOUR NOTEBOOK!
Possible solutions for #1-8:
(6,-6)
(-1,-8)
(10.-1)
(6,-9)
(-1,-1)
(5,6)
(7,-1)
(-1,3)
9. The sum of two numbers is 41 and their difference is 5. What are the numbers?
10. Four times one number added to another number is 36. Three times the first number minus
the other number is 20. Find the numbers.
11. At a sale on winter clothing, Cody bought two pairs of gloves and four hats for $43. Tori
bought two pairs of gloves and two hats for $30. What were the prices for the gloves and
hats?
12. Solve the system of equations by graphing: y = x – 4 and y = -x + 2.
13. Solve the system of equations using substitution. Then explain why this system should be
solved using substitution instead of elimination.
-5x + y = -2
-3x + 6y = -12
14. Challenge: You can actually solve #13 using elimination IF you multiply the top equation by 6
first. Try this, and see if you can get the same answer!