Upload
samuel-jefferson
View
220
Download
0
Tags:
Embed Size (px)
Citation preview
BELL RINGER
Yesterday you learned 3
different ways to solve
systems of linear equations.
Do you have a preference on
how to solve systems?
Explain.
SYSTEMS OF LINEAR EQUATIONS CONT.
Friday, February 6, 2014
QUICK REVIEW
You can solve systems of
linear equations by
graphing, substitution, or
elimination… but when do
you use which one?
WHEN DO YOU GRAPH?
If all equations are in the
form y =, then it is easiest to
graph (if you have a graphing
calculator), but you can always
graph if you solve for y first.
WHEN DO YOU SUBSTITUTE?
If only one equation is
solved for one variable,
then it is usually easiest to
use substitution; however,
you can always solve one
equation for a variable and
then substitute.
WHEN DO YOU USE ELIMINATION?
If the systems are already in
standard form (Ax + By = C),
then it’s easiest to use
elimination. Again, you can
always change the equations to
standard form and then use
elimination.
What are you going to
use for your variables?
How do you set up the
problem?
SYSTEMS IN WORD PROBLEMS
SOLVING BY MATRICES
First, get the system in standard form (Ax +
By = C). Then multiply the inverse of the
coefficient matrix by the constant matrix to
give you the value of the variables.
If you get an error message “ERR:
SINGULAR MAT”, then the equations are either
parallel lines or the same line, so there is no
solution or infinite solutions (you have to
check).
MATRIX EXAMPLES
1. 6x + 2y = 11 2. 6a – 9b = -
18
3x – 8y = 1 8a – 12b
= 24
Brenda’s school is selling tickets to a
spring musical. On the first day of ticket
sales the school sold 3 senior citizen
tickets and 9 child tickets for a total of
$75. The school took in $67 on the
second day by selling 8 senior tickets and
5 child tickets. What is the price each of
one senior citizen ticket and one child
ticket?
SYSTEMS IN WORD PROBLEMS
SYSTEMS IN WORD PROBLEMS
A boat traveled 336 miles
downstream and back. The trip
downstream took 12 hours. The
trip back took 14 hours. What is
the speed of the boat in still
water? What is the speed of the
current?
CLASSWORK
Solve the Odd Numbered systems
using any of the 4 methods you choose.
Feel free to use the same method for
each problem, but you are not limited
in your choice. SHOW YOUR WORK
HOMEWORK
Solve the Even Numbered systems
using any of the 4 methods you
choose. Feel free to use the same
method for each problem, but you are
not limited in your choice. SHOW
YOUR WORK