Question

solve for A, show work
18 - 6a = 4a - 4a + 12

Answer 1

so add up the values of a again, just pretend a is the same situation as x. Just a different letter right?

Answer 2

add 6a to the right, or the ones from the right to the left?

Answer 3

doesn't matter which way, just pick which side you want to go for.

So if I went with the left side.

I would keep -6a, subtract 4a, and add 4a.

Answer 4

if I did the right side, it would be the opposite; make sense?

Answer 5

example with the problem if you would?

Answer 6

So; you have:
\[18 - 6a = 4a - 4a + 12\]
if you wanted to go to the left hand side you can eliminate the variables on the right like so:
\[18 - 6a - 4a + 4a = 4a - 4a - 4a + 4a + 12\]
which can be simplified to \[18 - 6a = 12\]

Answer 7

get it?

Answer 8

so many 4a o.o

Answer 9

Yes; however, this problem has a shortcut.
If you notice \[18 - 6a = 4a - 4a + 12\]

the
\[4a - 4a + 12\]
can be simplified just as
\[12\]

Answer 10

understand?

Answer 11

yes ^.^

Answer 12

18 - 6a + 4a = 12

Answer 13

So since you can just simplify it right away, you an rewrite it without those because they cancel eachother out.

so you start with

\[18 - 6a = 12\]
which is what we got before.

Answer 14

Where'd you get the extra 4a?

Answer 15

18 - 6a = 4a - 4a + 12
18 - 6a + 4a = 12
i just brought it over

Answer 16

No, haha, I wasn't clear.

Answer 17

Think of it this way.
\[18 - 6a = 4a - 4a + 12\]
is simple because the 4a and the -4a negate each other and cancel out because they are exact opposites. make sense?

Answer 18

So since they are exact opposites; you can literally just pretend they don't even exist. It's like saying add one and subtract one. you're left with nothing.

Answer 19

ಠ_ಠ so
18 - 6a = 12
the 4a and -4a just dont exsist anymore and you simplify from there

Answer 20

yep yep yep
right on

Answer 21

would i subtract 18 and 12?

Answer 22

get your -6a to be alone.

Answer 23

you can do that by either subtracting 18 from both sides
or by adding 6a and subtracting 12 from both sides.

Answer 24

18 - 6a = 12
18 - 18 - 6a = 12 - 18
6a = -6
a = 1

Answer 25

yep good job :)
One thing though; you forgot to keep the negative on your -6a.

so -6a = -6
a = -6/-6
a = 1
so you were right just forgot to write the -

Answer 26

ಥ_ಥ so simple, yet so frustrating

Answer 27

s'all good we're making progress.

Answer 28

ive learned more on here in the last 10 hours, than i have in algebra since the beginning of the schoool year

Answer 29

18-6a=12 (subtract 18 from both sides)
-6a= -6 (divide through by -6)
a= 1