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Solve 4/(x - 2) + 1 = 3

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

Step by step

The question

Question: solve 4/(x − 2) + 1 = 3.

4x − 2 + 1 = 3

First: a bottom can never be 0.

x = 2 makes x − 2 0.

So x ≠ 2.

x ≠ 2

1 Remove the fractions

The bottom is (x − 2).

Times (x − 2) will remove it.

We multiply every part by (x − 2).

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

(x − 2) × 4x − 2 + (x − 2) × 1 = (x − 2) × 3

(x − 2) divided by (x − 2) is 1.

(x − 2) times 1 is (x − 2).

(x − 2) times 3 is 3(x − 2).

Write what is left.

No more fractions!

4 + (x − 2) = 3(x − 2)

2 Open the brackets

The 3 in front of the bracket multiplies every part inside.

So we write 3 times each part.

A bracket with a plus or nothing in front can just be removed.

4 + x − 2 = 3 × x + 3 × (−2)

Work out each multiplication.

4 + x − 2 = 3x − 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.

4 − 2 = 2.

4 − 2 = 2

Now we have 2 + x = 3x − 6.

2 + x = 3x − 6

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.

2 + x − x = 3x − 6 − x

+ x and − x make zero.

Cross them out.

3x − x = 2x.

3x − x = 2x

Now we have 2 = 2x − 6.

2 = 2x − 6

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

2x − 6 = 2

We want x by itself.

Two things are stuck to x: times 2 and − 6.

The − 6 is on the outside, so it comes off first.

Then the times 2.

5 Remove the − 6

To remove − 6, we add 6.

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

2x − 6 + 6 = 2 + 6

− 6 and + 6 make zero.

Cross them out.

2 + 6 = 8.

2 + 6 = 8

Now we have 2x = 8.

2x = 8

6 Remove the 2

2x means 2 times x.

We want just x.

To remove times 2, we divide by 2.

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

2x2 = 82

2 divided by 2 is 1.

So just x is left.

8 divided by 2 is 4.

82 = 4

So x = 4!

x = 4

7 Check

Let's check: put 4 in place of x.

First the left side.

Left: 44 − 2 + 1 = 42 + 1 = 2 + 1 = 3

Now the right side.

Right: 3

Both sides are 3.

So x = 4 is right!

Both sides equal 3

Let's look back.

First: remove the fractions.

Then: open the brackets.

Then: group like terms.

Then: get x on one side.

Then: remove the − 6.

Then: remove the 2.

Last: check.

Answer
x = 4

Your turn

Try this one yourself, then check:

3x − 2 + 1 = 4
Show the answer
x = 3

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