Solve by Graphing
Is (3, -1) a solution of the system:
x – 2y = 5
2x – y = 7
yes
Solve by substitution:
y = 5x – 10
y = 3x + 8
(9, 35)
Solve the system by elimination:
-x + y = 5
x - 5y = -9
(-4, 1)
Describe the graph of a system that has infinitely many solutions.
The graphs are the same.
Solve by graphing:
y =1/2x
y = -x + 3
(2,1)
Solve by substitution
y – 4x = 3
2x – 3y = 21
(-3, -9)
Solve the system by elimination:
-3x + 4y = 12
2x + y = -8
(-4, 0)
Describe the graphs of a system that has no solution.
The graphs are parallel lines.
Solve by graphing:
Y = x -2
2x + y = 1
(1,-1)
Solve by substitution:
x + 2y = -1
4x – 4y = 20
(3, -2)
Solve the system by elimination:
x – y = 4
x – 2y = 10
(-2, -6)
If the slopes of the lines are the same but the y-intercepts are different then the system has how many solutions?
No solution
Solve by graphing:
x + y = 2
y = x – 4
(3, -1)
Casey wants to buy a gym membership. One gym has a $150 joining fee and costs $35 per month. Another gym has no joining fee and costs $60 per month. In how many months will both gym memberships cost the same? What is the cost?
6 months. $360
Solve the system by elimination:
-2x + 3y = -15
3x + 2y = -23
(-3, -7)
Solve the system:
9y = 3x + 18
1/3 x – y = -2
Infinitely many solutions.
Explain how to check a solution of a system of linear equations.
Substitute the x and y values of the ordered pair. If both equations are true then the solution is correct.
Comcast cable has a $60 setup fee and costs $80 per month. Dish network has a $160 setup fee but charges $70 per month. Let y = total cost and x = number of months. Write the system of equations to represent this situation.
y = 80x + 60
y = 70x + 160
Harlan has $44 to buy 7 pairs of socks. Athletic socks cost $5 per pair. Dress socks cost $8 per pair. How many socks can Harlan buy?
4 pairs of athletic socks
3 pairs of dress socks
Solve the system:
X + 2y = -4
Y = 1/2x – 4
No solution