Steply

Solve x/2 >= 3

Step by step, with the reason for every step · Inequalities · Algebra 1

Step by step

The question

Question: solve x/2 ≥ 3.

This is an inequality.

The sign means greater than or equal to.

x2 ≥ 3

1 Remove the fraction

The bottom number is 2.

Times 2 will remove it.

We multiply every part by 2.

We do it on both sides.

Why both sides?

The sign compares the two sides.

If we change only one side, the answer can change.

2 is a positive number, so the sign stays the same.

2 × x2 ≥ 2 × 3

2 divided by 2 is 1.

Write what is left.

x ≥ 2 × 3

Do the multiplications.

No more fractions!

x ≥ 6

So x is greater than or equal to 6.

2 Show it on a number line

Books also write the answer like this.

It is called interval notation.

A square bracket means the end is in, like the filled circle.

∞ means it goes on for ever.

interval: [6, ∞)

3 Check

Let's test one number from the answer: 7.

We put it in place of x.

First the left side.

Left: 72

Now the right side.

Right: 3

Is 7/2 greater than or equal to 3?

To compare fractions, they need the same bottom number: 2.

72 ≥ 3

Multiply the top and bottom of each one by the same number.

72 ≥ 3 × 22

Same bottom, so we compare the tops.

7 is greater than or equal to 6.

True!

So the answer works.

72 ≥ 62

Let's look back.

First: remove the fraction.

Then: show it on a number line.

Last: check.

Answer
x ≥ 6

Your turn

Try this one yourself, then check:

x2 ≥ 4
Show the answer
x ≥ 8

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