MHB Substitution Method to solve linear simultaneous equation

AI Thread Summary
The discussion focuses on solving a system of linear equations using the substitution method. The user transformed the equations into a common denominator and derived two equations: 5y - 5x = 1 and 5y + 2x = 5. After substituting, they found x = 4/7, but expected the solution to be x = 0. A suggestion was made to multiply the first equation by 6 and simplify to potentially correct the solution. The conversation highlights the importance of careful manipulation of equations in the substitution method.
Yazan975
Messages
30
Reaction score
0
View attachment 8419

What I have done:

I changed all fractions to common denom and that gave me

5y-5x=1 (1) *I numbered the fractions
5y+2x=5 (2)

Then: 5y=5-2x

Substitute into equation 1
(5-2x)-5x=1
5-7x=1
x=4/7

Thing is my answer says I should be getting x=0

Any hints?
 

Attachments

  • Screen Shot 2018-09-18 at 5.48.11 PM-min.png
    Screen Shot 2018-09-18 at 5.48.11 PM-min.png
    10.6 KB · Views: 117
Mathematics news on Phys.org
When you multiply the first equation by $6$ and simplify, you should get $y-5x=1$.
 
Thread 'Video on imaginary numbers and some queries'

Thread 'Video on imaginary numbers and some queries'

Hi, I was watching the following video. I found some points confusing. Could you please help me to understand the gaps? Thanks, in advance! Question 1: Around 4:22, the video says the following. So for those mathematicians, negative numbers didn't exist. You could subtract, that is find the difference between two positive quantities, but you couldn't have a negative answer or negative coefficients. Mathematicians were so averse to negative numbers that there was no single quadratic...
View full post »
Thread 'Unit Circle Double Angle Derivations'

Thread 'Unit Circle Double Angle Derivations'

Here I made a terrible mistake of assuming this to be an equilateral triangle and set 2sinx=1 => x=pi/6. Although this did derive the double angle formulas it also led into a terrible mess trying to find all the combinations of sides. I must have been tired and just assumed 6x=180 and 2sinx=1. By that time, I was so mindset that I nearly scolded a person for even saying 90-x. I wonder if this is a case of biased observation that seeks to dis credit me like Jesus of Nazareth since in reality...
View full post »
Thread 'Imaginary Pythagoras'

Thread 'Imaginary Pythagoras'

I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...
View full post »

Similar threads

MHB Number patterns and sequences - Tn Term
Replies
1
Views
2K
B How can I properly distribute fractions when solving a set of linear equations?
Replies
7
Views
2K
B Need assistance with an unusual quadratic solution method
Replies
4
Views
1K
MHB Solving Equivalent Expressions Using Subtraction Method
Replies
6
Views
2K
Solve these simultaneous equations that involve vectors
Replies
6
Views
2K
MHB Evaluating Chosen Numbers in Quadratic Inequality
Replies
7
Views
2K
Solve for x and y in the given algebra problem involving fractions
Replies
25
Views
3K
MHB What is the Common Core method for solving 2x + 3x?
Replies
2
Views
2K
MHB Show that the solution is not suitable....
Replies
10
Views
3K
MHB Fixed point,, Jacobi- & Newton Method, Linear Systems
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top