Method for simultaneous equations of two or more variables, Mathematics

Assignment Help:

Method

In this method we eliminate either x or y, get the value of other variable and then substitute that value in either of the original equations to get the value of the other variable. Let us look at it.

We are given two equations 3x + 4y = 10 and 4x + y = 9. We write them as follows.

      3x + 4y = 10                                       ........(1)

      4x + y  = 9                                         ........(2)

In this example, let us eliminate y. Multiply equ. (2) by 4. We have

      4(4x + y = 9)

which is   16x + 4y = 36                             ........(3)

We observe that the coefficients of y in equations (1) and (3) are one and the same, and therefore, we subtract equ.(1) from equ.(3).

16x + 4y = 36   

- (3x + 4y = 10) 


13x + 0  = 26   


At this point one should remember that the signs of equation (1) should be changed before subtracting.

      13x      = 26

          x  = 26/13 = 2

We now substitute the value of x = 2 in either equ. (1) or (2). Let us substitute in equ. (2).

      4x + y      =   9

      4(2) + y    =   9

      8 + y        =   9

      y = 9 - 8   =   1

That is, the values of x and y for which both the equations are satisfied are x = 2 and y = 1.

We substitute these values in equ. (1) and check.

      3x + 4y       =   10

      3(2) + 4(1)  =   10

      6 + 4          =   10

      10              =   10

That is, LHS = RHS.


Related Discussions:- Method for simultaneous equations of two or more variables

Find the interval of validity, Solve the subsequent IVP and find the interv...

Solve the subsequent IVP and find the interval of validity for the solution. y' + (4/x) y = x 3 y 2 ,       y(2) = - 1,  x > 0 Solution Thus, the first thing that we re

Trigonometric ratios, to difine trigonometric ratios of an angle,is it nece...

to difine trigonometric ratios of an angle,is it necessary that the initial ray of the angle must be positive x-axis?

Indefinite integrals, Indefinite Integrals : In the past two chapters we'v...

Indefinite Integrals : In the past two chapters we've been given a function, f ( x ) , and asking what the derivative of this function was.  Beginning with this section we are now

Math, what is quantity ?

what is quantity ?

Solve the following word problems, 1.   The length of a rectangle is 2 time...

1.   The length of a rectangle is 2 times its width.  The area of the rectangle is 72          square inches. Find the dimensions of the rectangle.   2.   The length of a rec

expected value, Describe the distribution of sample means shapefor samples...

Describe the distribution of sample means shapefor samples of n=36 selected from a population with a mean of μ=100 and a standard deviation of o=12.  , expected value, and standard

representative value or an extreme value, A population forms a normal dist...

A population forms a normal distribution with a mean of μ=80 and a standard deviation of o=15. For every samples, compute the z-score for the sample mean and determine whether the

Counting, how do i count by 45s

how do i count by 45s

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd