The sum of two numbers is 12, and their difference is 6. What are the two numbers?
What are 3 and 9?
200
an ordered pair that is a solution of all equations in a system
What is a solution of a system?
200
3y-2x=4
x=3-y
What is (1,2)?
200
2x+6y= -12
3x-2y=4
What is (0,-2)?
200
2x+3y=15
-2x+3y= -5
What is (4,1)?
200
Twice a boy's age is 9 more than his brother's. The average of their ages is 12. How old are they?
What are 11 and 13?
300
systems that have the same solutions
What is an equivalent system?
300
2x-y= -8
3x+2y= -5
What is (-3,2)?
300
2x+y=2
3y= -6x+6
What is infinite solutions?
300
4x-6y= -26
-2x+3y=13
What are infinite solutions?
300
A girl has $6 in 36 coins (all quarters and nickels). How many of each does she have?
What are 21 quarters and 15 nickels?
400
solving one equation for a variable, substituting it in the other equation, and solving for the remaining variable
What is a substitution method?
400
2x-6y=30
2y=x+6
What is no solution?
400
5x+2y=2
3x+5y=24
What is (-2,6)?
400
y=4-x
3x+y=6
What is (1,3)?
400
A girl's cell phone costs $10 per month plus 10 cents per minute. Her friend's costs $3 per month plus 15 cents her minute. For what amount of talking time will the cost of these plans be the same?
What is 140 minutes?
500
multiplying equations so like terms have opposite coefficients, adding equations, and solving the result
What is an elimination method?
500
2a+4b= -5
3a-5b=9
What is (.5, -1.5)?
500
0.7x+2y=1.61
2x-0.3y=0.39
What is (0.3, 0.7)?
500
3x+2y=10
6x+4y=15
What is no solution?
500
A girl received $100 for her birthday. At the store she can buy 1 video game and 3 DVD's for $100. She could also buy 2 video games and 1 DVD for $100. How much does 1 video game and 1 DVD cost?