. I cannot multiply only one term, so I had to multiply through the whole denominator by it. If I'm multiplying through the whole denominator, I must also multiply the whole numerator by the same thing. Hence

a^2

on both.

Reply 185

Philip-flop

OP

18

Original post by RDKGames

Yep, and I knew I had to multiply by that because I wanted the (second) denominator to go away, so I had to choose

a^2

. I cannot multiply only one term, so I had to multiply through the whole denominator by it. If I'm multiplying through the whole denominator, I must also multiply the whole numerator by the same thing. Hence

a^2

on both.

Wow you really are a Maths wizard to me!! Are there any good videos/resources dealing with algebraic fractions when there are more than one term in the denominator and where there are fractions in the numerator and denominator? It's definitely something I need to work on :frown:

Reply 186

Naruke

11

Just to add on to the above post, remember

\frac{a^2}{a^2}

is just 1...

so you're not changing the value, you're just changing its form/appearance...

Reply 187

Naruke

11

Original post by Philip-flop

Wow you really are a Maths wizard to me!! Are there any good videos/resources dealing with algebraic fractions when there are more than one term in the denominator and where there are fractions in the numerator and denominator? It's definitely something I need to work on :frown:

r u srs u did this in chapter 1

Original post by Philip-flop

Wow you really are a Maths wizard to me!! Are there any good videos/resources dealing with algebraic fractions when there are more than one term in the denominator and where there are fractions in the numerator and denominator? It's definitely something I need to work on :frown:

Not really, it's nothing significant enough to make videos about, just a simple manipulation you get used to when you deal with enough of these cases.

Reply 189

Philip-flop

OP

18

Original post by Naruke

r u srs u did this in chapter 1

In these kind of cases I'm not that comfortable with it :frown:

I never would have known to multiply by..

\frac{a^2}{a^2}

...for the example above.

(I know my Maths knowledge sucks but I never said I was a natural)

(edited 7 years ago)

Reply 190

Naruke

11

Original post by Philip-flop

In these kind of cases I'm not that comfortable with it :frown:

I never would have known to multiply by..

\frac{a^2}{a^2}

...for the example above.

(I know my Maths knowledge sucks but I never said I was a natural)

The reason why maths is such a great thing is because there are so many ways to go about solving problems. What that RDK kid did above was just one way of solving it...

You could have easily just did

c^2 \equiv \frac{\frac{16}{a^2}}{1-\frac{16}{a^2}}

(common denominators, you learned this in the earlier chapters to!)

c^2 \equiv \frac{\frac{16}{a^2}}{\frac{a^2 - 16}{a^2}}

c^2 \equiv \frac{16}{a^2} \times \frac{a^2}{a^2 - 16}

(You probably learned this in KS1...

\frac{\frac{a}{b}}{\frac{c}{d}} \Rightarrow \frac{a}{b} \times \frac{d}{c})

from there it's just a simple case of cancelling the

a^2

and multiplying.

I don't think there is a lot of gaps in your knowledge. I think you just need to practice using the skills you've acquired in previous chapters in unusual circumstances.

(edited 7 years ago)

Original post by Naruke

The reason why maths is such a great thing is because there are so many ways to go about solving problems. What that RDK kid did above was just one way of solving it...