1. Solving Quadratic Systems
Topic 7.7

2. Ways to Solve Systems 1. Graphing 2. Algebraically Substitution
Elimination can be used, but substitution is typically easier

3. Solving by Graphing Rewrite each equation for “y=”
If you take the square root, remember that the answers are “±” the expression
Graph the equations
On the Casio, Press “F5” then “F5” again (isect)
Make sure to choose the two equations that are intersecting
If there is more than one intersection, move the direction key to get the others

4. Example: Solve the systems of equations graphically
Answers: (0,2) and (4,6)
Answers: (5,4) and (2,-4)

5. Solving Algebraically
Use Substitution
Solve the easiest equation for one variable
Plug it into the second equation to get the value(s) of one variable
Plug those value(s) back into the first equation to get the value(s) of the other variable

6. Example 1: Rewrite 2nd equation for y
Substitute into 1st equation for y
Solve for x
Plug into 2nd equation

7. Example 2: Rewrite first equation for y2
Substitute y2 in the 2nd equation
Substitute x back in the 1st equation
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