Thread: need help

2A/3=8+4A

my problem is to figure out what A is alone but my answer doesnt match the book, i know its either A=12/5 or A=-2.4 but my answer doesnt come close.

first i tried it 2A/3=8+4A then take 4A from both sides to get -2A/3=8, times by 3 to get rid of it. -2A=24, then devide by -2, A= -12.

Hello,

Your mistake is here :

then take 4A from both sides to get -2A/3=8

If you take 4A from both sides, it's :

8=(2A/3)-4A

But to substract two elements, they gotta have the same denominator. So write 4A=12A/3 and then do the substraction.

Originally Posted by Moo

Hello,

Your mistake is here :

If you take 4A from both sides, it's :

8=(2A/3)-4A

But to substract two elements, they gotta have the same denominator. So write 4A=12A/3 and then do the substraction.

sorry i dont understand exactly why you increased the 2A to 12A, am i suppose to look at 2A/3 as a fraction?

It would be a really big help if you could explain alittle step by step, i havent done this type of math for a awhile and trying to get a jump on it again so.. kind tell me in the most simple way please

Originally Posted by Jgleer

sorry i dont understand exactly why you increased the 2A to 12A, am i suppose to look at 2A/3 as a fraction?

It would be a really big help if you could explain alittle step by step, i havent done this type of math for a awhile and trying to get a jump on it again so.. kind tell me in the most simple way please

I'll try

2A/3=8+4A.

--------------------
What you did :
(2A/3)-4A=-2A/3

Remember the rules of operations (pemdos or bodmas), the division comes before the substraction !

What you did here is first substract 4A to 2A and then divide by 3. This is false.

2A/3 - 4A = 8

Multiply both sides by 3 in order to get rid of the division.

--> 2A - 12A=24

and now you can solve

Originally Posted by Moo

I'll try

2A/3=8+4A.

--------------------
What you did :
(2A/3)-4A=-2A/3

Remember the rules of operations (pemdos or bodmas), the division comes before the substraction !

What you did here is first substract 4A to 2A and then divide by 3. This is false.

2A/3 - 4A = 8

Multiply both sides by 3 in order to get rid of the division.

--> 2A - 12A=24

and now you can solve

Thank you so much Moo!, that made alot more sense. When i would multiply by 3 i just did it to 8 and not to 4A. I understand taking 2A/3=8+4A Then getting to 2A=24+12A now. after that i would substract 12 and get -10A/24 = -2.4.

Thanks again Moooo