MYTUTOR SUBJECT ANSWERS

509 views

How do I expand (3x + 6)(x + 2) ?

Firstly, this is a classic GCSE question that crops up time and again, so it's worth making sure that you can expand brackets blindfolded and with your arms tied behind your back before you walk into the exam. These can be easy marks in the bag every time and once you've got the hang of it, they're not too difficult.

The trick to expanding brackets is to always remember FOIL. That's First, Outside, Inside and Last. Now what does that mean? I hear you ask. Well each of the letters in FOIL refer to a different pair of numbers in the bracket.

The F stands for First. What this means is that you need to multiply the first numbers in the brackets together. The first thing in the first bracket is 3x and the first thing in the second bracket is x, so multiply these together to get 3x^2.

The O stands Outside. If we think of the brackets together now, we can see that there are two things on the outside of the brackets, and that is the 3x and the 2. We now multiply these together to get 6x.

The I stands for Inside. Just as we did for the Outside numbers, we imagine the two brackets as one thing, but this time we take the two Inside numbers. In our example, this is 6 and x. Multiply these two together to get 6x.

Finally, L stands for Last. Remember when we multiplied the the First two numbers in each bracket together? Now we just multiply the Last two numbers in each bracket together. Here they are 6 and 2, so we multiply them to get 12.

Now we have our four numbers, we simply add them all together to get our result:

(3x + 6)(x + 2) = F + O + I + L

=3x^2 + 6x + 6x + 12

=3x^2 + 12x + 12

That's the trick to expanding brackets. Just follow the simple steps every time and you've got full marks every time!

Joshua B. GCSE Maths tutor, A Level Maths tutor, A Level Further Math...

1 year ago

Answered by Joshua, a GCSE Maths tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

460 SUBJECT SPECIALISTS

£24 /hr

Sioned D.

Degree: Law (Bachelors) - University College London University

Subjects offered:Maths, History+ 4 more

Maths
History
English
Biology
.LNAT.
-Personal Statements-

“Hello! I'm a University College London Final year Law Student with a great deal of tutoring experience in English, Maths, Sciences and Entrance Exams. ”

£18 /hr

Liam M.

Degree: Mathematics (Bachelors) - St. Andrews University

Subjects offered:Maths, Physics

Maths
Physics

“I have a real passion for Maths and Physics and would relish the opportunity to pass this passion on to others! ”

£20 /hr

Eszter H.

Degree: Modern Languages (Bachelors) - Durham University

Subjects offered:Maths, History+ 6 more

Maths
History
German
English and World Literature
English Literature
English Language
.MLAT (Modern Languages)

“I am a Modern Languages (German and Spanish) student at Durham University. I believe that the knowledge of foreign languages is becoming more and more important, thus I am devoted to help every student who want to develop their German...”

About the author

Joshua B.

Currently unavailable: for new students

Degree: Mathematics (Masters) - Durham University

Subjects offered:Maths, Further Mathematics

Maths
Further Mathematics

“Hi! I’m Josh, a third year on a four-year Mathematics course. I got 100% in both my Maths IGCSE and A-Level, and did all 18 A-Level modules.”

You may also like...

Other GCSE Maths questions

Work out the ratio between the surface area of sphere of radius 6cm and the total surface area of a hemisphere of radius 9cm.

How do I find the roots and and coordinates of the vertex of the graph y = 2x^2 + 4x - 8 ?

solve the quadratic: 2x^2 - 8x + 6

Factorise x^2 + 7x + 10

View GCSE Maths tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok