(Algebra) why is this wrong?

Hi,

For this question, you should notice that in the second to last step, the 5a and 1 should be negative values since you have moved these quantities to opposite sides of the equation.

Therefore, you equation at this point should look as follows:

-5a = -1 + 5b

Now, divide both sides of the equation by -5 to get:

a = [-1 + 5b] / -5 <==== FINAL ANSWER

I hope that helps you out! Please let me know if you have any other questions!

1/(a - b) = 5
5a - 5b = 1
5a = 5b + 1
a = (5b + 1)/5

Answer: a = (5b + 1)/5 OR a = b + 1/5—that's right!

Proof (substitute a with b + 1/5):
1/([b + 1/5] - b) = 5
1/(b + 1/5 - b) = 5
1/(1/5) = 5
1(5/1) = 5
5 = 5

both your answerr and the book answer is the same

your answer = (1+5b) / 5 = 1/5 + 5b/5 = 1/5 + b = book answer apparently !!!!!!!!!!!

well done

your answer is correct
a=(1+5b)/5
a=1/5 + 5b/5
a=1/5 +b
a=b+1/5

You are always supposed to "simplify comepletely," whatever that means.
I generaly assume that the form that is easiest to enter into a calculator is the simplest, but the book sometimes disagrees :)

1/(a-b)/5 =5

1=5a-5b
-----------------
5

1/5=a-b
b+1/5=1-b+b

a=b+1/5

You have set out your working clearly to reach :-

a = ( 1 + 5b ) / 5

a = 1/5 + (5b)/5

a = 1/5 + b

a = b + 1/5

Both answers are acceptable.

You were correct except the given answer goes one step further and divides throughout by 5

1/5 = 1/5
5b/5 = b

So [1 + 5b]/5 does equal b + 1/5

Your answer is right, but you need to simplify it.

a = (1 + 5b)/5
a = 1/5 + 5b/5
a = 1/5 + b
a = b + 1/5

1/(a-b) = 5
1 = 5(a-b)
1 = 5a - 5b
-5a = -5b-1
a = -5b/-5 -1/-5
a = b + 1/5

You have to divide both side by 5
5a = 1+5b
a = 1+b