factor 4y^2-9

Question

factor 4y^2-9

zehanz · Answer

It is of the form a² - b² = (a + b)(a - b).

Here: a² = 4y² and b² = 9.
So if you can figure out a and b, you can factor it!

anonymous · Answer

would it be (4y+3)(4y-3) ?

whpalmer4 · Answer

Close, but not quite.  4*4 = 16.

whpalmer4 · Answer

$$a^2 = 4y^2$$Take square root of both sides
$$a=\sqrt{4y^2} = ?$$

anonymous · Answer

oh haha so it would be (2y+3)(2y-3)

zehanz · Answer

Right!

whpalmer4 · Answer

By the way, learning to recognize difference of squares like this is an important trick in your bag of factoring tricks.

anonymous · Answer

okay! haha blonde moment! :)

zehanz · Answer

We all have that once in a while!

anonymous · Answer

haha this is my 6 th one today :/

whpalmer4 · Answer

And whenever you think you've solved something, or factored it, it's not a bad idea at all to expand it out or plug in the solution and make sure that your answer works!

zehanz · Answer

You used them up for the whole week already!

whpalmer4 · Answer

Might have to wear a wig for a few days ;-)

anonymous · Answer

haha thanks guys! and its natural I cant help it. and the wig wouldnt hide anything. honestly ive tried that and it didn't work:(

zehanz · Answer

Just learn to live with it ;)

anonymous · Answer

haha I do! I just accept im a natural blonde but at least im not a bimbo!

zehanz · Answer

Good luck with your maths problems!

whpalmer4 · Answer

I have a friend who is a natural brunette, but she prefers to be blonde, and often pulls it off quite convincingly :-)