651 views

### Q: How to solve the simultaneous equations 3x+2y=7 and 5x+y=14

When solving simultaneous equations you are aiming to use both equations together to find out the value of x and y for values that with ‘fit’ in each equation.

3x + 2y = 7

5x + y = 14

If we subtract these equations from each other in a way that we end up eliminating y, when can find the value of x. The way we do this is to multiply equation 2 by 2, remembering to multiply both sides of the equation. This gives

2. 10x + 2y = 28

Now, when we subtract equation 1 from equation 2 we get

(10x – 3x) + (2y - 2y) = 28 – 7

7x = 21

x = 3

Now we have found the value of x we can substitute it back into equation 1 to find the value of y.

3x + 2y = 7 and x = 3

9 + 2y = 7

2y = -2

y = -1

1 year ago

Answered by Katherine, a GCSE Maths tutor with MyTutor

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

#### 649 SUBJECT SPECIALISTS

£18 /hr

Degree: Bsc Biomedical Sciences (Bachelors) - Queen Mary, London University

Subjects offered:Maths, Science+ 7 more

Maths
Science
Human Biology
Extended Project Qualification
.UKCAT.
-Personal Statements-
-Medical School Preparation-

“A science fanatic that loves sharing that knowledge and is here to help with your grades and getting into University!”

£20 /hr

Degree: Mathematics (Bachelors) - Imperial College London University

Subjects offered:Maths

Maths

“21 years old. 2 years experience teaching. BSc Mathematics Imperial College London. Studying MSc in Aerospace Dynamics (please ask for references).”

£20 /hr

Degree: Biomedical Sciences (Bachelors) - Cardiff University

Subjects offered:Maths, Russian+ 1 more

Maths
Russian
English

“Hopeful doctor in the making looking to help you reach your goals! I'm interested in everything so I am sure we will have something in common.”

Currently unavailable: for regular students

Degree: Chemistry (Masters) - Edinburgh University

Subjects offered:Maths, Chemistry+ 1 more

Maths
Chemistry
Biology

“All About Me Hi, my name is Katherine I am from Edinburgh and am currently in my 2nd year studying Medicinal and Biological Chemistry, also in my home town, at the University of Edinburgh.  I have always had a real passion for science...”

MyTutor guarantee

|  3 completed tutorials

### You may also like...

#### Posts by Katherine

What mass of carbon dioxide is produced from burning 100 grams of ethanol in oxygen according to this reaction: C2H5OH + 3 O2 --> 2 CO2 + 3 H2O

Q: How to solve the simultaneous equations 3x+2y=7 and 5x+y=14

#### Other GCSE Maths questions

Make X the subject of the equation (9x-7)/3 = 8y

Bag A contains £7.20 in 20p coins. Bag B contains only 5p coins. The number of coins in bag B is three-quarters of the number of coins in bag A. How much money is in bag B?

How do I complete the square of an equation?

Solve 5x – 2 > 3x + 11

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