Transcript 4. Not all relationships are purely additive or

LESSON
14.3
Writing Equations from
Tables
How can you use an equation to show a relationship between
two variables?
Texas Essential
Knowledge and Skills
The student is expected to:
Expressions, equations, and relationships—6.6.B
Write an equation that represents the relationship between independent and
dependent quantities from a table. Also 6.6.C
Mathematical Processes
6.1.B
Use a problem-solving model that incorporates analyzing given information, formulating
a plan or strategy, determining a solution, justifying the solution, and evaluating the
problem-solving process and the reasonableness of the solution.
ADDITIONAL EXAMPLE 1
Write an equation that expresses y in
terms of x. ( What do I have to do to x to get to y?)
A
y = 3x
B
When going from
smaller to larger you
are either multiplying
or adding
+3
OR x3
Either +5 or x 3.5
Which rule works for
the entire table?
y=x+5
ADDITIONAL EXAMPLE 2
Meredith is playing a video game. She earns the
same number of points for each alien she captures.
She earned 750 points for capturing 5 aliens and
1,350 points for capturing 9 aliens. Write an
equation to represent the relationship. Then solve
the equation to find how many points Meredith will
earn if she captures 27 aliens.
p = 150a, where p represents the number of points
and a represents the number of aliens captured;
4,050 points
14.3 LESSON QUIZ
6.6.A
Write an equation that expresses y in terms
of x.
1.
y = 5x
2.
y=x–3
3. Jaime bought 2 puzzles for $5.00 and 3 puzzles
for $7.50. Write and solve an equation to find
the cost of 15 puzzles.
c = 2.50p; $37.50
4. A submarine descends to –100 feet in 2 minutes
and –250 feet in 5 minutes. Write and solve an
equation to find the depth of the submarine in 8
minutes.
d = –50m; –400 feet
Not all relationships are purely additive or
multiplicative. Find the y-values in the following
tables. Use the order of operations. Compare and
contrast these relationships with additive and
multiplicative relationships.
1. y = 2x + 1
Not all relationships are purely additive or
multiplicative. Find the y-values in the following
tables. Use the order of operations. Compare and
contrast these relationships with additive and
multiplicative relationships.
2. y = 3x – 2
Not all relationships are purely additive or
multiplicative. Find the y-values in the following
tables. Use the order of operations. Compare and
contrast these relationships with additive and
multiplicative relationships.
3.
Not all relationships are purely additive or
multiplicative. Find the y-values in the following
tables. Use the order of operations. Compare and
contrast these relationships with additive and
multiplicative relationships.
4.
How can you use an equation to show a relationship
between two variables?
Use a table to find the relationship between the
two variables. Use that relationship to write an
equation.