MYTUTOR SUBJECT ANSWERS

373 views

Solve this pair of simultaneous equations (1) 5x+2y=20 and (2) x+4y=13

To solve these equations, our aim is to find a value of x and a value of y that satisfy both equations at the same time. By satisfy we mean, if we plug our values in for x and y then the left hand side and right hand side of each equation will equal eachother.

First to find x and y we must try and eliminate either x or y to find the other.

Lets try and eliminate x.

We can write equation (2) with x as the subject by subtracting 4y from both sides, like so:

x=13-4y

Now we can substitute this into equation (1) to eliminate x giving:

5(13-4y) + 2y = 20

Expanding the brackets gives

65 - 20y + 2y = 20

Now we collect all the y's onto one side and the constants onto the other giving:

45 = 18y

Then divide through by 18 to give y=5/2

Now we substitute this into either equation (1) or (2) for y to find x.

With (1) : 5x + 2(5/2) = 20, 5x = 15, x=3

With (2) : x + 4(5/2) = 13, 5x=15, x=3

So our solution is x=3, y=5/2. It isn't necessary to show x's value with both equations but it can be useful to check your answer is correct!

Jenny H. A Level Maths tutor, GCSE Maths tutor

9 months ago

Answered by Jenny, a GCSE Maths tutor with MyTutor


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

579 SUBJECT SPECIALISTS

£20 /hr

Akhil P.

Degree: Medicine (Bachelors) - Imperial College London University

Subjects offered:Maths, Physics+ 6 more

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

“First Year Medical student at Imperial College. Studies all 3 sciences and Maths at A-levels and did an EPQ(4 A*s and an A)”

£18 /hr

Sophia H.

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. ”

£20 /hr

Ellen T.

Degree: Economics (Bachelors) - LSE University

Subjects offered:Maths, Physics+ 2 more

Maths
Physics
Economics
-Personal Statements-

“Hi! I study Economics at LSE. With previous tutoring experience, I am keen to provide genuine advice and create an engaging learning environment. ”

About the author

£18 /hr

Jenny H.

Degree: Economics and Mathematics (Bachelors) - Bristol University

Subjects offered:Maths

Maths

“I'm an Economics and Mathematics student at the University of Bristol. Maths has always been one of my passions, I enjoy learning new areas of the field and encouraging others to have the same enthusiam for the subject as I do. I hope ...”

MyTutor guarantee

You may also like...

Posts by Jenny

How do I differentiate y=(4+9x)^5 with respect to x?

Solve this pair of simultaneous equations (1) 5x+2y=20 and (2) x+4y=13

Other GCSE Maths questions

Solve the simultaneous equation: 6x+y = 27 3x-2y = 6

How can i add algebraic fractions, such as 1/(1-x) + 2/x

can you show me how to solve simultaneous equations?

A right-angled triangle has base 10cm and height 4cm. What is the area of the triangle?

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