MYTUTOR SUBJECT ANSWERS

671 views

Given 4x+7y=25 and 2x+5y=17, identify x and y by solving the simultaneous equations

First thing we have to do is to eliminate one of the variables, either x or y (it doesn’t matter which one). In order to achieve that, we aim to have the same co-efficient (number in front of x or y) of a variable in both equations.

In this example, we can observe that no co-efficient is the same so we have to do some manipulation first before eliminating a variable!

Multiplying 2x+5y=17 by 2, give us 4x+10y=34 (Remember to multiply by 2 all the numbers)

Now that we have the same x co-efficient in both equations we can eliminate the x variable by subtracting one equation from the other:

    4x + 10y = 34

–  4x + 7y = 25

3y=9

 y=3

Hence, we can substitute y in one of the initial equations e.g. 2x+5y=17

2x+5(3) = 17

2x=17-15

2x=2

x=1

Therefore, the variables are x=1 and y=3

Andreas O. GCSE Chemistry tutor, GCSE Maths tutor, GCSE Physics tutor

1 year ago

Answered by Andreas, a GCSE Maths tutor with MyTutor


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

635 SUBJECT SPECIALISTS

£18 /hr

Rhys T.

Degree: Medicine (Other) - Cambridge University

Subjects offered:Maths, Science+ 6 more

Maths
Science
Physics
Chemistry
Biology
.UKCAT.
.BMAT (BioMedical Admissions)
-Medical School Preparation-

“Cambridge Medical student tutoring Maths and Science, I am young and enthusiast for my subjects.”

MyTutor guarantee

£36 /hr

Gina J.

Degree: Economics with French (Bachelors) - Bristol University

Subjects offered:Maths, Spanish+ 2 more

Maths
Spanish
French
Economics

“Private tutor of Economics, Maths and French with six years of experience. I am passionate about teaching!”

£18 /hr

Mihai P.

Degree: Natural Sciences (Bachelors) - Cambridge University

Subjects offered:Maths, Chemistry+ 2 more

Maths
Chemistry
Biology
-Medical School Preparation-

“I would like to share my passion for science and help you discover the key patterns which govern our world.”

About the author

Andreas O.

Currently unavailable: for new students

Degree: Medicinal and Biological Chemistry (MChem) (Masters) - Edinburgh University

Subjects offered:Maths, Physics+ 2 more

Maths
Physics
Chemistry
Biology

“Hey there!! My name is Andreas and I study Medicinal and Biological Chemistry (MChem) at University of Edinburgh (UoE). I consider myself passionate in the field of Science and Maths and at the same time I try to learn more and become ...”

MyTutor guarantee

You may also like...

Posts by Andreas

Given 4x+7y=25 and 2x+5y=17, identify x and y by solving the simultaneous equations

What is the volume of carbon dioxide released at room temperature and pressure when 6.2 g of copper carbonate reacts with excess dilute sulfuric acid?

Other GCSE Maths questions

The normal price of a television is £1200. It is reduced to £970. Work out the percentage reduction. Give your answer to 1 decimal place.

Factorise x^2-7x+12

How do I solve a quadratic equation?

Factorise 8a^2 - 50b^2 completely.

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