Solving by Substitution
x + y = 12
x = 5
(5, 7)
y = 2x − 2
y = −x + 4
(2,2)
x − y = 11
2x + y = 19
(10, -1)
-6x + 5y = 1
6x + 4y = −10
(-1, -1)
Where did Ms. Guay go to college?
Bridgewater State University
x = 3y+1
2x + 4y = 12
(4, 1)
y =1/3x
y = −2x − 7
(-3, -1)
4x + 8y = 20
−4x + 2y = −30
(7, -1)
5x + y = 9
10x − 7y = −18
(1, 4)
What day of the week is Christmas on this year?
Tuesday
y = 3 – x
5x + 3y = -1
(-5, 8)
y = 2x + 3
y =6/3x − 5
No Solution
−4x − 2y = −12
4x + 8y = −24
(6, -6)
5x – y = -9
4x + 3y = -11
(-2, -1)
On a standard traffic light, is the green on the top or bottom?
Bottom
y = 2x +1
y = −3x + 11
(2, 5)
3y = 3x + 6
y = x + 2
Infinitely Many Solutions
8x + y = −16
−3x + y = −5
(-1, -8)
y = 5x − 7
−3x − 2y = −12
(2, 3)
Who is on the 100 dollar bill?
Benjamin Franklin
2x − y = 5
−3x + 7y = 9
(4, 3)
y= -1/2x -2
y= -3/2x +2
(4, -4)
−4x + 9y = 9
x − 3y = −6
(9, 5)
x + 3y = 1
−3x − 3y = −15
(7, -2)
What is the largest state in the United States of America?
Alaska