The Town Recreation Department rents out their batting cage. During the summer, it costs $5 to rent a bat and $7 per hour to use the batting cage. During the winter, it costs $3 to rent a bat and $4 per hour to use the batting cage. Write a systems of equations to represent the situation.
y= 7x + 5
y= 4x + 3
14) What is the solution to the system of linear equations?
(2,2)
If we were to do substitution and have a graph of the same system of equations would we get the same solution?
Yes.
Every equation graphs a specific line so no matter how you solve, you get the same solution!
(Graphs are definitely easier, but we don't always have graphed systems!)
Solve the systems of equations using substitution:
y=3x-10
x=2
(2,-4)
How many solutions does the system of linear equations have?
One! (-4,-6)
On the windowsill is a plant that is 14 centimeters tall. It is growing 8 centimeters per week. A second plant, which is 16 centimeters tall, is on the coffee table. It is growing 7 centimeters per week. Write a systems of equations to represent the situation.
y= 8x + 14
y= 7x + 16
What is the solution?
(-1,1)
What is the first step when solving a system of linear equations using the SUBSTITUTION method?
Isolate the variable
Solve the systems of equations using substitution:
y=2x-10
y=4x+8
(-9,-28)
How many solutions does the system of linear equations have?
y = 3x - 5
y = 3x + 7
Zero or None
Kelly and Sallie both went bowling last weekend, but not together. Kelly went during open bowling time, paying $3 for shoe rental and $6 per hour. Sally went on family night, when each hour was $4 and shoe rental was $1. Write a systems of equations to represent the situation.
y= 6x + 3
y= 4x +1
Solve Using Graphing:
y = 5/3x + 2
y = -3
What is your new (one) equation after performing substitution?
y=2x
3x+y=20
3x+(2x)=20 or
5x=20
Solve the systems of equations using substitution:
y = -2x - 9
3x -6y = 9
(-3, -3)
How many solutions does the system of linear equations have?
y = (-5/3)x + 3
y = (1/3)x - 3
One
Mr. Galosh, the owner of two car dealerships in Morristown, is holding a contest to see which one can sell the most cars. Morristown Cars has already sold 10 car, and Galosh Auto has sold 12 cars. Going forward, the salespeople at Morristown Cars think they can sell 3 cars per day, whereas the salespeople at Galosh Auto are aiming for sales of 1 car per day. Write a systems of equations to represent the situation.
y= 3x + 10
y= x + 12
Solve the systems of linear equations by graphing:
How would you isolate x in this equation?
6y+x=20
subtract 6y from both sides to get:
x=20-6y
Solve the systems of equations using substitution:
2x - y = 6
x = y + 5
(1, -4)
How many solutions does the system of linear equations have?
y = 3x + 9
2y = 6x + 18
Infinitely many solutions
How do we write solutions to systems of linear equations?
(x,y)
Solve this by graphing:
2x - y = 4
x + 3y = 3
(3,2)
Use the substitution method to solve the system of linear equations:
y=2x
3x+y=20
Solution: (4,8)
Use the substitution method to solve the system of linear equations:
6x + 2y = 10
y = -3x -4
No solution
How many solutions does the system of linear equations have?
y = 2x - 5
4y = 8x - 5
Zero or None