Transcript Write the equation of the line… Solve by Graphing

Write the equation of the line…

Write the equation of the line…

Through (4, 5) and (6, 9)
Write the equation of the line…

Write the equation of the line…

Solve by Graphing
Section 3.1
According to one plan, the repair cost is $50 plus $10per
hour. Another plan is $75 plus $5 per hour. Which plan
should I choose? When are they the same?
System of Equations

Consists of 2 or more equations with 2 or
more variables
Solution

A point (x, y) is said to be a solution to a
system of equations if it satisfies both
equations.
Given:
6 x  9 y  15

x  y  4

Is (9, 5 ) a solution?

Is (7, 3) a solution?
Definitions

Consistent – has at least one solution



Dependent – Infinite number of solutions
Independent – has exactly one solution
Inconsistent – has no solution
Consistent
Consistent
Independent
Dependent
Inconsistent
Solve by graphing:
 y  3x  2

x  3y  4
Solve by graphing:
 x  4 y  20

6 x  4 y  8
Solve by graphing:
4 x  3 y  9

8 x  6 y  12
To Solve with the calculator:



First Solve each equation for y
Press y= and put the first equation into y1
and the 2nd equation into y2
Press 2nd TRACE - #5 intersect
Solve w/Calculator:
 y  3x  2

9 x  3 y  6
Solve w/Calculator:
Solve w/Calculator:
Solve w/Calculator:
Solve w/Calculator:
Homework

Worksheet