View Full Version : Need help with solving equations of form ax + b = c

11-03-2008, 09:36 PM
Hello, I am about to start a new section in algebra. I was wondering if I could get some tips on how to solve equations of the form ax + b = c.

11-03-2008, 10:27 PM
Can't help unless you put up an actual problem.

11-03-2008, 11:18 PM
... how to solve equations of the form ax + b = c

Denis is right; you've provided only partial information.

IF you want to solve this form for the symbol x, then it's always the same two steps.

1) Subtract b from both sides to isolate the term which contains the symbol x

ax = c - b

2) Divide both sides by a to isolate the symbol x

x = (c - b)/a


~ Mark :)

11-04-2008, 06:49 PM
oh, ok. the question is 2x + 6 = 21. I don't even know how to do the first step. My teacher just tells us the pages to read and then she goes to the tenth graders. I read the whole thing and I still don't get it. I told her but she didn't even care and she said," Tough, I guess you will have to wait till next class." Thats when it is due! I can't wait until then. If I get a bad grade in Algebra I'm going to be grounded! :(

11-04-2008, 07:08 PM
Follow instructions given by mmm4444bot above.

11-05-2008, 12:56 AM
... 2x + 6 = 21. I don't even know how to do the first step ...

Can you identify the values of a, b, and c in this exercise?

Do you know how to perform an arithmetic operation (such as subtraction or division) on both sides of an equation?

Here's an example; solve for x.

7x - 4 = -30

Isolate the term 7x by adding 4 to both sides. (This is the same as subtracting -4 from both sides.)

7x + 4 - 4 = 4 - 30

7x = -26

Isolate x by dividing both sides by 7.

(7/7)x = -26/7

x = -26/7

The main things to remember are (1) you're trying to get x all by itself on one side of the equal sign, and (2) you do this by performing operations to BOTH sides of the equation (i.e., whatever you do to one side of an equation, you must always do to the other side, as well). It's easy to solve equations of this form if you know how to do arithmetic with positive and negative numbers, and you know the multiplication table, and you're able to work with fractions.

Now, you try.

If you need more help with your exercise, then please show whatever work you can accomplish and try to say something about why you're stuck.


~ Mark :)

11-06-2008, 10:42 PM
Oh, ok. I get it a little bit know. I will try it tomorrow. My grandmother asked my teacher if I could have till Monday to turn it in and she said yes. So I will have plenty enough time to do it ! :D