How to Use TI-83 for Factoring
Alg I Part 2
"The greatest common factor”
(GCF) is the greatest factor that
divides two numbers.
For instance,
the GCF of 9 and 12 is 3.
2
TI-83
Find the GCF of 45 and 60 (two numbers).
1. Go to
MATH
, then NUM in
screen.
2. Enter 9: gcd (
3. Enter 45, 60)
4. You will get answer 15. That is
the GCF of 45 and 60.
3
TI-83
You cannot use TI to find
GCF for variables
3
18x2
3x
x
6x2
x
6x
1
Multiply all numbers on the left side. That will be the GCF.
GCF of 18x2 and 3x is 3  x = 3x
4
TI-83
You cannot use TI to find GCF
for More than 2 numbers
2
24
64
104
2
12
32
52
2
6
16
26
3
8
13
GCF of 24, 64, and 104 is 23 = 8
5
What is the first type of
factoring you look for?
the GCF.
6
TI-83 (Method 1)
1. Choose any number and store to x.
7
2. Enter the problem to be factored 30x + 75
3. Set “ = “ to one of the possible answers. The “=“
sign is under 2nd
d
Math
Math Test #1 =. Then
enter.
4. After “=“ sign, enter 15(2x+5)
8
Correct !
5. If
0, the answer is N0T correct.
6. If
1 appears, the answer is correct!!
(You can use x, y, for z too. Try!)
9
TI-83 (Method 2)
1.Go to Y=
2.Enter the expression into Y1=.
3. Enter the answer into Y2=
4. Move to the left of the Y2= and
choose the circle.
5. When answer is correct, the
animated circle will be riding on
top of the first graph.
10
TI-83
Examples that I cannot use TI
Method 1
It does not give me an answer, but
just says yes (1) or no (0).
x2 + 6x3 = x2 (y – y2 z)
?
11
TI-83
Examples that I cannot use TI
Method 2
I cannot use it for more than 1
variables.
y1 = x2 y – xy2 z
?
12