Bell Ringer
Evaluate each expression for a = 4.
1. 6a – 21
2. 13 + 2a
3. 0.5a + 8
4. 2.4a + 7
5. 33 – 5a
6. 1.6(9 – a)
Solutions
1. 6(4) – 21 = 24 – 21 = 3
2. 13 + 2(4) = 13 + 8 = 21
3. 0.5(4) + 8 = 2 + 8 = 10
4. 2.4(4) + 7 = 9.6 + 7 = 16.6
5. 33 – 5(4) = 33 – 20 = 13
6. 1.6(9 – 4) = 1.6(5) = 8
Answers to Homework
Answers to Homework
Today’s Objectives
Represent an equation in two variables as a function
Make a table of solutions for a linear equation or function
Graph a linear equation or function using a table of solutions
Rewrite the equation in function notation.
y = 5x - 7
y= 5x - 7
f(x)= 5x - 7
2y = 8x - 10
y= 4x - 5
f(x)= 4x - 5
x – 7y = 14
y= x/7 - 2
f(x)= x/7 - 2
1. Solve each for y
2. Replace “y” with “f(x)”
Make a table of solutions to obtain at least three sets of coordinates
that satisfy each equation.
y = 5x - 7 x y
2y = 8x - 10 x y
y = 4x - 5
-1 -12
-1 -9
0 -7
0 -5
1 -2
1 -1
2 3
2 3
Use the table of solutions from a previous problem to graph
following solutions.
y = 5x - 7 x y
2y = 8x - 10
y = 4x - 5
-1 -12
0 -7
1 -2
2 3
the
x
y
-1
0
1
2
-9
-5
-1
3
Determine which of the ordered pairs are solutions for the given
equation.
1. Substitute each value into equation.
2. Solve
2x – 5y = 9
3. Are the two sides equal?
(4,5)
( 12 , 3 )
( 4.5 , 0 )
2(4) – 5(5) = 9
2(12) – 5(3) = 9
2(4.5) – 5(0) = 9
8 – 25 = 9
24 – 15 = 9
9–0=9
-17 = 9
9=9
9=9
NO
YES
YES
Write the specific solution for each equation in ordered pair form.
x – y = 3, if x = 8
8–y=3
-y = -5
y=5
x + 2y = - 4, if y = 1
x + 2(1) = -4
x + 2 = -4
x = -6
1. Substitute each value into equation.
2. Solve
For the equation x = 6, complete the given ordered pairs
( ,2) ; ( ,-3) ; ( ,1).
1. x is 6 for ANY value of y.
2. Rewrite each ordered pair.
(6,2)
( 6 , -3 )
(6,1)
Assignment
Pages
391-392
#’s 20-70 All