Steply

Solve x/(x - 3) = 3/(x - 3) + 2

Step by step, with the reason for every step · Rational equations · Algebra 2

Step by step

The question

Question: solve x/(x − 3) = 3/(x − 3) + 2.

xx − 3 = 3x − 3 + 2

First: a bottom can never be 0.

x = 3 makes x − 3 0.

So x ≠ 3.

x ≠ 3

1 Remove the fractions

The bottom is (x − 3).

Times (x − 3) will remove it.

We multiply every part by (x − 3).

We do it on both sides, so they stay equal.

(x − 3) × xx − 3 = (x − 3) × 3x − 3 + (x − 3) × 2

(x − 3) divided by (x − 3) is 1.

(x − 3) divided by (x − 3) is 1.

(x − 3) times 2 is 2(x − 3).

Write what is left.

No more fractions!

x = 3 + 2(x − 3)

2 Open the brackets

The 2 in front of the bracket multiplies every part inside.

So we write 2 times each part.

x = 3 + 2 × x + 2 × (−3)

Work out each multiplication.

x = 3 + 2x − 6

3 Group like terms

Terms are the parts between the + and − signs.

Like terms are the same kind: same letters, same powers.

Plain numbers go together.

3 − 6 = −3.

3 − 6 = −3

Now we have x = −3 + 2x.

x = −3 + 2x

4 Get x on one side

There is x on both sides.

We want x on one side only.

So we remove the x from the left side.

To remove x, we take away x.

We do it on both sides, so they stay equal.

x − x = −3 + 2x − x

x and − x make zero.

Cross them out.

2x − x = x.

2x − x = x

Now we have 0 = −3 + x.

0 = −3 + x

Let's swap the two sides, so x is on the left.

−3 + x = 0

5 Remove the − 3

We want x by itself.

The − 3 is in the way.

To remove − 3, we add 3.

We do it on both sides, so they stay equal.

−3 + x + 3 = 0 + 3

− 3 and + 3 make zero.

Cross them out.

0 + 3 = 3.

0 + 3 = 3

So x = 3!

x = 3

But x = 3 is the x that is not allowed: it makes a bottom 0.

So there is no solution.

x = 3 makes a bottom 0: no solution.

Let's look back.

First: remove the fractions.

Then: open the brackets.

Then: group like terms.

Then: get x on one side.

Last: remove the − 3.

Answer
x = 3 makes a bottom 0: no solution.

More from Rational equations

The whole lesson: Rational equations →