colormekaylee
New member
- Joined
- Aug 1, 2009
- Messages
- 12
[3a - (2a-3)] [3a + (2a-3)]
I got 3a^2 - 4a^2 + 9
= -a^2 + 9
Is this right?
I got 3a^2 - 4a^2 + 9
= -a^2 + 9
Is this right?
colormekaylee said:[3a - (2a-3)] [3a + (2a-3)]
One way to do it:
= [3a - 2a + 3][ 3a + 2a - 3]
= [a + 3][5a - 3]
= 5a[sup:lg6720ko]2[/sup:lg6720ko] - 3a + 15a - 9
= 5a[sup:lg6720ko]2[/sup:lg6720ko] + 12a - 9
There is another way of doing it where you can use the formula x[sup:lg6720ko]2[/sup:lg6720ko] - y[sup:lg6720ko]2[/sup:lg6720ko] = (x-y)(x+y)
I got 3a^2 - 4a^2 + 9
= -a^2 + 9
Is this right?
colormekaylee said:[3a - (2a-3)] [3a + (2a-3)]
I got 3a^2 - 4a^2 + 9
= -a^2 + 9
Is this right?