Download Diamond and Box Factoring

Solving
Quadratics using
the box method
Solve the x-box way
1. Solve 3x2 -13x -10
x
-5
3x
3x2
-15x
+2
2x
-10
(3)(-10)=
-30
2
-15
-13
3x2 -13x -10
(x-5)(3x+2)=0
x-5=0
3x+2=0
x=5
3x=-2
x=-2/3
Examples
Solve using the x-box method.
2. x2 + 4x – 12
6
-12
4
-2
x
+6
x
x2
6x
-2
-2x
-12
Solution: x2 + 4x – 12
(x + 6)(x - 2)=0
x+6=0
x-2=0
x=-6
x=2
Examples
3. 2x2 - 5x – 7
-14
-7
2
-5
2x
x
+1
2x²
2x
Solution: 2x2 - 5x – 7
(2x - 7)(x + 1)=0
-7
-7x
-7
2x-7=0
x+1=0
Examples
4. 15x2 + 7x – 2
3x
-30
10 -3
5x
7
-1
+2
15x²
10x
-3x
-2
Solution: 15x2 + 7x – 2
(3x + 2)(5x - 1)=0
3x+2=0
5x-1=0
Activity!
• Solve the quadratic equation by
factoring and match it with the
solutions on the right.
• After you complete the task, raise
your hand and I will come and check
it off.
Homework time!
• Remember to set your equation equal
to 0!
• Together: #3, 5, 16