(3) Algebra Problem: Can you help?
The question is:
3. Factorise 12ab – 18a2
and the answers are:
1. 3b(4b – 6a)
2. 6a(2b – 3a)
3. 2a(6a – 3b)
Can anyone help me please with how to GET to the answer?
So far I’ve tried finding the factors which multiply to make minus 18 but nothing I’ve found adds up to make positive twelve. Also the answer is arranged completely differently to the (x+yada)(x+yada) that i’m used to.
Thank you
Observing members:
0
Composing members:
0
Answers
No matter, I’ve figured it out
The question you should be asking are:
What is the greatest common factor to 12 and 18? don;t get hung up on the sign.
What is a common denominator to ab and a^2 ?
divide by those two factors combined, and you’ll get your answer.
It’s 2
I worked backwards from the answer instead.
@zenvelo I’ll make a note of your approach to help me with similar questions. Thank you.
May I suggest that you learn the correct notation for this problem.
You’re looking for the factors of:
12ab – 18a^2
not
12ab – 18a2
The term “a-squared” is written in formats such as this (and Excel spreadsheets, too) as
a^2
Response moderated (Off-Topic)
Answer this question