SOLUTION: need help on this equation.. 5(4-k)= -10k i tried to do it but not sure. 5(4-k)=-10k 5+5k=-10k -10k+5k=5 -5=5 k=-1 ?

Algebra ->  Equations -> SOLUTION: need help on this equation.. 5(4-k)= -10k i tried to do it but not sure. 5(4-k)=-10k 5+5k=-10k -10k+5k=5 -5=5 k=-1 ?      Log On


   

Question 51338: need help on this equation..

5(4-k)= -10k



i tried to do it but not sure.
5(4-k)=-10k
5+5k=-10k
-10k+5k=5
-5=5
k=-1 ?
Found 2 solutions by rapaljer, THANApHD:
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
You seem to have several errors!

It should be this:
5(4-k)=-10k
20-5k=-10k

Add +5k to each side:
20 - 5k + 5k = -10k + 5k
20 = -5k

Divide both sides by -5:
20%2F%28-5%29+=+%28-5k%29%2F%28-5%29+
-4+=+k

You probably need to back up a bit. Why don't you go to my webpage by clicking on my tutor name "rapaljer" anywhere in algebra.com, then look for "Basic Algebra", "Samples of Basic Algebra: One Step at a Time", Chapter 1, Equation Solving. Also, you may need the REST of Chapter 1 before you do this!!

In addition, while you are at my website, look for "Math in Living Color" for Basic Algebra. These and all the other Lesson Plans on algebra.com may be helpful to you.

R^2 at SCC

Answer by THANApHD(104) About Me  (Show Source):
You can put this solution on YOUR website!

i tried to do it but not sure.
5(4-k)=-10k
5+5k=-10k
-10k+5k=5
-5=5
k=-1 ?

actually U'r problem is with signs
5+5k=-10k (this step is correct)
5-5+5k = -10k-5 (you can do any kind of arithmatic stuff in both sides of an equation)
5k+10k=-5-10k+10k
15k = -5
15k/15=-5/15
k = -1/3