Graphing
Where do Start when I am graphing a line?
The Y-intercept
Solve the system of equations by substitution.
y=x-14
y=-6x
(2,-12)
Solve the system of equations using elimination.
x+y=82
x-y=26
(28,54)
The sum of two numbers is 82. The difference of the same two numbers is 26.
Write the 2 equations that represent this scenario.
x+y=82
x-y=26
Where can I find my slope?
With the x
If my slope is 3 how do I move?
Up 3 right 1
Solve the system of equations with substitution.
y=3x-7
4x+y=-14
(-1,-10)
Solve the system of equations using elimination.
2x+5y=3
4x-5y=21
(4,-1)
Tiana ordered flowers and bushes. The first order was for 24 flowers and 6 bushes. The Toal cost of the first order was $144. The second order was for 18 flowers and 3 bushes. The total of the second order was $90. write the two equations that represent this scenario.
24x+6y=144
18x+3y=90
Where can I find my y-intercept?
by itself
What does a graph look like when there is one solution? No solution? Infinitely many solutions?
an X with one intersection, parallel lines, the same line
Solve the system of equations by substitution.
-3x+4y=6
-x+2y=8
(10,9)
Solve the system of equations with elimination.
8x+2y=12
8x+4y=16
(1,2)
Mr.Bowler cooked a total of 45 hamburgers and hot-dogs at a cookout. He cooked twice as many hot dogs as hamburgers. Write the two equations the represent this scenario.
x+y=45
2x=y
What do I need to always check before I look for my slope and y-intercept?
My y is by itself and it is in slope-intercept form (y=mx+b)
Graph the line y=3x+3
Start at 3 and go up 3 right 1.
How many solutions does the system of equations have?
y=2x+3
4x-2y=8
no solutions
Solve the system of equations with elimination.
2x+5y=-13
x+3y=-5
(-14,3)
Bella runs a lemonade stand where she sells small cups of lemonade for $1.25 and large cups for $2.50. On Saturday, Bella sold 155 cups of lemonade and earned a total of $265. Write the two equations that represent this scenario.
1.25S+2.50L=265
S=L=155
y=5x-3
What is my slope?
What is my y-intercept?
5 and -3
Graph the line y=-2x-1
start at -1 and go down 2 right 1
How many solutions does the system of equations have?
y+11=2x
3y-6x=-33
infinitely many solutions
Solve the system of equations using elimination.
6x+2y=14
4x+3y=1
(4,-5)
Tickets for an adult meal, a, for a dinner are $7 each and childrens meal, c, cost $3 each. There were 139 people who purchased a meal and a total of $661 was earned in sales. Write the two equations that represent this scenario.
7a+3c=661
a+c=139
2y-4x=6
What is my slope?
What is my y-intercept?
2 and 3