8th grade math?

Question

Ok i've been trying to figure out how to do equations with varables on both sides but i don't really understand can sombody solve this problem and put steps to it please?thankyou =D

7x+12=13x

Answer 1

Ho'kay

basically, an equation is like a counter weight....the thing that has two weights on both sides to keep it level.

so what you do to one side, you have to do to the other to make it remain equal.

So the first thing you want to do is get all the variables on the same side:

7x - 7x +12 = 13x -7x

I basically subtracted 7x from both sides to get all the variables on one side equal to another.

so you are now left with

12 = 6x

now, you want to find out what x is so to do that you have to get x on its own.

so divide both sides by 6 now

12/6 = 6x/6

The 6's on the the one side cancel each other out and you are now left with your answer

2 = x

rewrite it the other way

and x = 2

theres your answer

Answer 2

Okay, I'm an 8th grade teacher, so I don't agree with people just giving you the answer, what I'm going to do is try to explain it to you so that you can understand the problem and do them on your own from now on.

7x+12 = 13x the first thing you want to do is put all
the 'x' on the same side of the equation.
Since an equation is like a scale, it has
to be balanced on both sides. The next
step is this:
7x-7x+12 = 13x-7x Remeber that the 'scale' what must
keep the balanced at all times, that's
why you have to send the 7x to the other
side of the equation. I tell my students,
that sending it to the other side means
that it's changing to it's opposite.
Therefore + = -, - = +, / = x, x = /,
exponant = root, and root = exponant.
Since 7x-7x = 0, then you can cross
them off. With addition and substraction
you need to have a 0, with multiplication
and division you need a 1. Those are
the numbers that do not change the
equation when they're put into a
problem. Ex. 10-0 = 10, 20+0 = 20.
You'll now have this:
12=13x-7x Okay, so since you're dealing with the
same variable, you can put them
together, that means that you'll have to
substract 13-7 which gives you 6.
Since you didn't get rid of the x, you
have to put it after the answer to the
substraction.
You now have this:
12=6x Okay, now you want to isolate the
variable, this means that you have to
send the 6 to the other side of the
equation. Remember that a
multiplication becomes a division.
Since 6x really means 6 multiplied by
x, then you must divide the 6 by 6, do
the same to the other side (in order to
keep the perfect balance)
You now have this.
12/6 = 6x/6 Since 6 divided by six gives you 1
you can cross off both 6's. In
multiplications and divisions 1 does
not affect the outcome of your
calculations (ex1000 x 1 = 1000,
1000 / 1 = 1000)
12/6 = x now just calculate the answer to 12/6
2 = x Tadda!

If you want to be supper sure of your answer, do a verification, it's really easy, just rewrite the original math problem and then substitute all of the x's for 2's. Do all of the calculations and if you finish with the same number on both side of the = then you've succeded! Congrats!
7x+12 = 13x
7(2) + 12 = 13(2)
14 + 12 = 26
26 = 26

Now celebrate the correct answer! YAHOO!!!!!!! YOUPI!!!!!!!!! Yay!!!!!!!!!!!!

Good luck!

Answer 3

Do the same operation to both sides of the equation until you get either x = number or number = x

7x + 12 = 13x

12 = 6x {subtract 7x}

2 = x {divide by 2}

We could have done:

7x + 12 = 13x

7x = 13x - 12 {subtract 12}

- 6x = - 12 {subtract 13x}

x = 2 {divide by - 6}

Answer 4

7x+12=13x Given
12=6x Subtract 7x from both sides. It cancels out on the left.
2=x Divide both sides by 6. The six cancels out on the right.
x=2 :D

Answer 5

the question is 7x+12=13x

we will take 7x on the other side & we'll change the sign
so, 12=13x-7x
or 12=6x
now, 12/6=x
therefore 2=x
or x=2
so the value of x is 2

Answer 6

7x + 12 = 13x

12 = 13x - 7x

12 = 6x

6x = 12
12
x = --
6

x = 2

Answer 7

7x + 12 =13x
-12 -12
7x=13x-12
-13x -13x
-6x=-12
divide both sides by -6
x=2

Answer 8

7x+12=13x
12 = 13x - 7x
12 = 6x
2 = x

Hint: You can move terms from one side of the = sign to the other side as long as you change the sign of the term.. So 7x becomes -7x when moved to the other side of the = sign.

Answer 9

To answer a percentage problem, you have to first change the percent into a decimal. So, if you are multiplying by 62%, you would change that to .62. Then just multiply the number by .62. For example. 62% of 50. You would multiply 50 times .62. (Remember to multiply as normal, then move the decimal over two places.) You would get 31.0 as your answer. Remember that in a word problem, "of" often refers to multiplication.

Answer 10

7x-13x=-12
-6x=-12
x=2