Step by step
The question
Question: divide (6x² + 5x − 4) by (2x − 1).
1 Set it up
We write it like long division with numbers.
2x − 1 goes outside, 6x² + 5x − 4 inside.
2 First part of the answer
Divide the first parts: 6x² divided by 2x is 3x.
We write it on top.
Multiply: 3x times (2x − 1) is 6x² − 3x.
We write it under, with a minus: we take it away.
6x² take away 6x² is 0.
That is why we chose 3x.
5x take away −3x is 8x.
Bring down the next part: −4.
3 Second part of the answer
Divide the first parts: 8x divided by 2x is 4.
We write it on top.
Multiply: 4 times (2x − 1) is 8x − 4.
We write it under, with a minus: we take it away.
8x take away 8x is 0.
That is why we chose 4.
−4 take away −4 is 0.
The last part is 0.
So nothing is left over.
So the answer is 3x + 4.
Nothing is left over.
4 Check
Let's check with a number: x = 2.
First the start: 6x² + 5x − 4.
Now the answer: (2x − 1) times (3x + 4).
Both give 30.
So the answer is right!
Let's look back.
First: set it up.
Then: first part of the answer.
Then: second part of the answer.
Last: check.