# Thread: Solving Algebraic Expressions with too many variables........ Help!!!!

1. ## Solving Algebraic Expressions with too many variables........ Help!!!!

Hey guys!! I'm having a little trouble understanding my algebra 1 homework, so any help will be greatly appreciated!!!

I have some problems that look like this:

SOLVE
6(b+7)=b-4

I don't understand how to solve this when there is a variable on both sides of the equation.....

Thanks!!

2. So you do know that 6(b+ 7)= 6b+ 42? Your equation is the same as 6b+ 42= b- 4. What do you get if you subtract b from both sides? What do yu get if you subtract 42 from both sides.

3. Originally Posted by HallsofIvy
So you do know that 6(b+ 7)= 6b+ 42? Your equation is the same as 6b+ 42= b- 4. What do you get if you subtract b from both sides? What do yu get if you subtract 42 from both sides.
If you subtract b from both sides i think you get 6+42=-4, and then u subtract 42 and get 6=-44.

But six is not equal to negative forty-four.
??

4. Originally Posted by lillybeth
If you subtract b from both sides i think you get 6+42=-4, and then u subtract 42 and get 6=-44.

But six is not equal to negative forty-four.
??
Actually, I think it did it wrong...

would it be 6b=-44?

I'm not exactly certain, neither one makes much sense to me, would the answer be a decimal? b= -7.2???

5. Originally Posted by lillybeth
Hey guys!! I'm having a little trouble understanding my algebra 1 homework, so any help will be greatly appreciated!!!

I have some problems that look like this:

SOLVE
6(b+7)=b-4

I don't understand how to solve this when there is a variable on both sides of the equation.....

Thanks!!
6b + 42 = b - 4

6b + 42 - b = b - 4 - b (subtract b from both sides)

6b - b + 42 = b - b - 4

5b + 42 = -4

5b + 42 - 42 = -4 - 42 (subtract 42 from both sides)

5b = - (42 + 4)

5b = -46

$\dfrac{5b}{5} \ = \ \dfrac{-46}{5}$ ... (divide both sides by 5)

b = -9.2

Lillybeth - I strongly suggest that you talk to your teacher and get this type of problems "totally right" - without any confusion.

Also go to:

http://www.purplemath.com/modules/solvelin.htm

and work through the example problems there.

6. Originally Posted by Subhotosh Khan
6b + 42 = b - 4

6b + 42 - b = b - 4 - b (subtract b from both sides)

6b - b + 42 = b - b - 4

5b + 42 = -4

5b + 42 - 42 = -4 - 42 (subtract 42 from both sides)

5b = - (42 + 4)

5b = -46

$\dfrac{5b}{5} \ = \ \dfrac{-46}{5}$ ... (divide both sides by 5)

b = -9.2

Lillybeth - I strongly suggest that you talk to your teacher and get this type of problems "totally right" - without any confusion.

Also go to:

http://www.purplemath.com/modules/solvelin.htm

and work through the example problems there.

Oh, okay I get it now.

Thankyou so much for your help!!!!!!!!!!!