Steply

Simplify (3x - 6)/(x - 2)

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

Step by step

The question

Question: simplify (3x − 6)/(x − 2).

A fraction with x in it is called a rational expression.

3x − 6x − 2

We make it simpler like a number fraction.

6/9: both have a 3 in them.

3/3 is 1, so 2/3 is left.

We do the same with brackets.

69 = 2 × 33 × 3 = 23

1 Factor the top

We look at the top: 3x − 6.

= 3x − 6

3 and 6 can both be divided by 3.

We take 3 out.

What is left goes in the bracket.

3x ÷ 3 = x, −6 ÷ 3 = −2

So the top is 3(x − 2).

= 3(x − 2)

2 Cross out the same

Careful!

We cross out only a whole bracket, or a whole x, that multiplies everything.

Never one part of a bracket.

Careful: only whole brackets cross out

Now we write the fraction with the factors: 3(x − 2)/(x − 2).

= 3(x − 2)(x − 2)

(x − 2)/(x − 2) is 1.

Cross them out.

3 Write what is left

What is left is 3.

= 3

One more thing: the bottom of the question can't be 0.

So x can't be 2.

x ≠ 2

4 Check

Let's check with a number: x = 1.

First in the question.

We get 3.

Question: 3(1) − 61 − 2 = −3−1 = 3

Now in our answer.

We get 3 too.

Answer: 3

Both are 3.

So 3 is right!

Let's look back.

First: factor the top.

Then: cross out the same.

Then: write what is left.

Last: check.

Answer
= 3

Your turn

Try this one yourself, then check:

3x − 12x − 4
Show the answer
3

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