MYTUTOR SUBJECT ANSWERS

866 views

Solve: 3(x - 2) = 21

First you look at BIDMAS, which determines the order in which functions are completed, [Brackets, Indices, Division, Multiplication, Addition, Subtraction], which says we deal with the brackets first, so we expand the bracket by multiplying everything in the bracket by whats outside it; in this case 3.

3x - 6 = 21

We then need to reaarange the equation to get x on its own, remember that when anything goes over to the other side of an equals sign it changes to the opposite of its function (positive - negative or multiply - divide). So the -6 goes across and becomes a positive 6:

3x = 21 + 6

3x = 27

Then the multiply by three goes over and becomes a divide:

x = 27/3

x = 9

Mia V. GCSE Chemistry tutor, A Level Chemistry tutor, GCSE Maths tuto...

8 months ago

Answered by Mia, a GCSE Maths tutor with MyTutor


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

336 SUBJECT SPECIALISTS

£18 /hr

Kyle R.

Degree: Mathematics (Masters) - Oxford, Corpus Christi College University

Subjects offered: Maths, Further Mathematics + 2 more

Maths
Further Mathematics
.STEP.
.MAT.

“Hi! I'm Kyle, a 2nd year Oxford undergraduate studying Maths at Corpus Christi College. I aim to be an understanding and friendly face, whilst being thorough with the material I cover. I've acheived A* grades in Maths, Further Maths a...”

£18 /hr

Rhys M.

Degree: Economics (Bachelors) - Durham University

Subjects offered: Maths, History+ 2 more

Maths
History
Geography
Economics

“About Me I am currently studying Economics at Durham University. Economics is a very broad subject, so I am very passionate about many other subjects and do a lot of reading around my subject. I was delighted to be awarded the top spo...”

£22 /hr

Nicolo G.

Degree: BSc Government and Economics (Bachelors) - LSE University

Subjects offered: Maths, History+ 2 more

Maths
History
Economics
Biology

“I am currently a student of economics and government at the London School of Economics. I developed a passion for economics during my IB diploma studies and I hope I will be able to instill that passion in you as well. I am very patien...”

About the author

£18 /hr

Mia V.

Degree: Chemistry (Masters) - Durham University

Subjects offered: Maths, Physics+ 1 more

Maths
Physics
Chemistry

“I am a Chemistry student at Durham University. I've always had a passion for learning new things, but most importantly helping others to learn new things too! I'm an open, patient individual who aims to put you at ease with your scien...”

You may also like...

Posts by Mia

A pendulum has a frequency of 0.80 Hz, calculate the periodic time of the pendulum.

Explain why fluorine and chlorine are in the same group of the periodic table.

Solve: 3(x - 2) = 21

What is a disproportionation reaction?

Other GCSE Maths questions

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

How is the quadratic formula used?

Make x the subject of the equation y = {2(1+x)}/(3x+1)

13 - 3 × 4+2 Simple question that lots of people get wrong

View GCSE Maths tutors

Cookies:

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

mtw:mercury1:status:ok