What variable will be eliminated?
2x-9y=2
x+9y=5
The y variable will be eliminated
Find the point of intersection.
(5,2)
Solve the systems of equations using substitution.
x = 5
x + y = 12
(5, 7)
What kind of lines have no solution?
Parallel lines
What is the slope intercept form?
y=mx+b
When solving by elimination, what is the first step?
Make sure that the variables are lined up. (equations are in standard form)
Find the point of intersection.

(2, -7)
Solve the systems of equations using substitution.
y = 2x
x + y = 9
(3, 6)
How can we determine the solution to a system of equations when graphing?
The solution is where the lines of the equations intersect.
What is Standard Form of an Equation?
Ax + By = C
What must you do to eliminate the x?
2x-3y=9
2x+7y=1
Multiply either equation by a negative 1
Solve by graphing. Round to the nearest tenth if necessary.
x + y = 10
xy = 21
{(3, 7), (7,3)}
Solve the systems of equations using substitution.
x -5y=36
2x+y=-16
(-4,-8)
Determine whether the given point is in the solution set to the given system.
(-1, 5, 2)
2x + y - z = 1
x - 2y + z = -9
x - y - 2z = -8
No
The answer to a linear system of equations is an _______
Ordered pair/Coordinate point
An x and a y!
2x - 3y = -2
3x - 2y = 12
(8,6)
Solve using a graphing calculator. Round to the nearest tenth if necessary.
y = x2
y = 2x
{(0, 0),(2,4)}
Solve the systems of equations using substitution.
1/2x - 2/3y = -2
4y = 3x+ 12
Infinitely many solutions - Dependent System
{(x,y) | 4y = 3x+12}
x + y + z = 6
x - y - z = -4
2x + y - z = 3
{(1, 3, 2)}
The perimeter of a rectangle is 120 ft. If the width were doubled and the length were increased by 12 ft, the perimeter would be 200.5 ft.
Width 28.25 ft
Length 31.75 ft
Solve using elimination method
3x - y=9
2y - 6x=7
No solution, Inconsistent System
The solution set is empty
Solve the system by graphing on a calculator. Round to the nearest hundredth if necessary.
y = 6x+7
y = x2
{(7, 49), (-1, 1)}
Solve the systems of equations using substitution.
y = 2x + 1000
0.05x + 0.06y = 400
(1/3, -5)
x + y - z = 0
3x - y + 3z = -2
x + 2y - 3z = -1
{(-2, 5, 3)}
The City Zoo has different admission prices for adults and children. When three adults and two children went to the zoo, the bill was $54.75. If two adults and three children got in for $49, then what is the price of an adult ticket and child ticket?
Adult tickets are $13.25
Child tickets are $7.50