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Solve x/(x + 2) + 1 = 6/(x + 2)

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

Step by step

The question

Question: solve x/(x + 2) + 1 = 6/(x + 2).

xx + 2 + 1 = 6x + 2

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) × xx + 2 + (x + 2) × 1 = (x + 2) × 6x + 2

(x + 2) divided by (x + 2) is 1.

(x + 2) times 1 is (x + 2).

(x + 2) divided by (x + 2) is 1.

Write what is left.

No more fractions!

x + (x + 2) = 6

2 Open the brackets

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

x + x + 2 = 6

3 Group like terms

Terms are the parts between the + and − signs.

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

All the x terms go together.

x + x = 2x.

x + x = 2x

Now we have 2x + 2 = 6.

2x + 2 = 6

We want x by itself.

Two things are stuck to x: times 2 and + 2.

The + 2 is on the outside, so it comes off first.

Then the times 2.

4 Remove the + 2

To remove + 2, we take away 2.

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

2x + 2 − 2 = 6 − 2

+ 2 and − 2 make zero.

Cross them out.

6 − 2 = 4.

6 − 2 = 4

Now we have 2x = 4.

2x = 4

5 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 = 42

2 divided by 2 is 1.

So just x is left.

4 divided by 2 is 2.

42 = 2

So x = 2!

x = 2

6 Check

Let's check: put 2 in place of x.

First the left side.

Left: 22 + 2 + 1 = 24 + 1 = 12 + 1 = 12 + 22
= 32

Now the right side.

Right: 62 + 2 = 64 = 32

Both sides are 3/2.

So x = 2 is right!

Both sides equal 32

Let's look back.

First: remove the fractions.

Then: open the brackets.

Then: group like terms.

Then: remove the + 2.

Then: remove the 2.

Last: check.

Answer
x = 2

Your turn

Try this one yourself, then check:

xx + 2 + 1 = 4x + 2
Show the answer
x = 1

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