# Math Help - rearranging

1. ## rearranging

2a+5c=af+7c

How could i re arrange this to make a the subject...Thanks

2. Originally Posted by Chez_
2a+5c=af+7c

How could i re arrange this to make a the subject...Thanks
$2a+5c=af+7c$

$2a-af=7c-5c$

$a(2-f)=2c$

$a=\frac{2c}{2-f}$

3. Originally Posted by Chez_
2a+5c=af+7c

How could i re arrange this to make a the subject...Thanks
$2a+5c=af+7c$
$\therefore 2a - af = 7c - 5c$
$\therefore a(2-f) = 2c$
$\therefore a=\frac{2c}{(2-f)}$

Factorising is the key to success when you have two of the same variable that needs to be made the subject.