i am a total math-moron...?

Question

how do you expand an equation? i learned it awhile ago but i cant remember...

Answer 1

2(x+12)= 10
expanded:
2x+24= 10

Answer 2

Hi there.

I know exactly how you mean. When I was in middle school, math was hell. I didn't get it. But now, in 10th grade, I'm taking two math classes (one AP a year ahead, and one my regular grade's honors math class) and doing wonderfully! Anything is possible.

Expanding is the opposite of factoring (if you've done that yet!) It makes use of the distributive property, which goes like this:
a(b + c) = ab + ac
What you do is, if you are multiplying one number by a quantity of numbers, you multiply the one number outside the parentheses by each number inside the parentheses, and then add the products together. Here's an example:

3(5 + 9)
We'll multiply 3 and 5, then multiply 3 and 9, then add the two numbers together!
3(5+9) = (3)(5) + (3)(9) = 15 + 27 = 42

Now, if you have some variables in there, it'll work the exact same way.
5(y + 9) = 5y + 5(9) = 5y + 45
You can't expand that expression any further, so we'll just leave it like 5y + 45.

Expanding is basically just removing all of the parentheses in statements or equations and then combining like terms. Lets try one more complicated one.

3(x + 5) + 4(x + 2) - 2 (x + 7) + x(4 + 9)
Okay. This might look hard. But bear with me. We just want to simplify this expression so that there are no parentheses left. To do this, we first want to complete anything we can simplify within the parentheses. I see that there is a 4 + 9. There are no unknowns in there, so we can simplify that to 13.

3(x + 5) + 4(x + 2) - 2(x + 7) + x(13)
Okay. We can also remove the parentheses around 13 now, since there's only one number in there!

3(x + 5) + 4(x + 2) - 2(x + 7) + 13x
Now lets expand the first expression:

3(x) + 3(5) + 4(x + 2) - 2(x + 7) + 13x
Okay. That should look familiar. Lets simplify it further.

3x + 15 + 4(x + 2) - 2(x + 7) + 13x
Alright. Now lets simplify 4(x + 2).

3x + 15 + 4(x) + 4(2) - 2(x + 7) + 13x
Lets get rid of those parentheses!

3x + 15 + 4x + 8 - 2(x + 7) + 13x
Okay. Now we have 2(x + 7). Or wait, do we really? In reality, that is actually a -2 multiplied by x + 7. So we need to treat that like (-2)(x + 7). Remember, subtracting is the same as adding a negative. Lets rewrite it that way.

3x + 15 + 4x + 8 + (-2)(x + 7) + 13x
Now we can continue.

3x + 15 + 4x + 8 + (-2)(x) + (-2)(7) + 13x
Now lets multiply it out.

3x + 15 + 4x + 8 + (-2x) + (-14) + 13x
Now we can combine some like terms. Lets combine all of the x's. We have a +3x, a +4x, a -2x, and a +13x. If you add all of together, 3+4-2+13 = 18. So we now have:

18x + 15 + 8 + (-14)
Now we need to simplify the constants. We have 15 + 8 - 14. That comes out to 9.

So, finally, we are left with 18x + 9. See! That wasn't so hard, was it?

Hopefully this helped!!

Answer 3

It simple, to expand on the last answer 2(x+12)= 10 all you have to do is mulitply what is outside the brackets the 2 in this case by what is inside the brackets (x+12) in this case. so 2 times x is 2x and 2 time 12 is 24 so 2x+24= 10 thats it.

Answer 4

first of all- don't be down on yourself, if you need further math help, email me with your email or and your im.
mathforum.org/equations
adelaider.com
quickmath.com
softpedia.com/equation-expand

Answer 5

i wish i new