Solve the equation by substitution method 5x+2y+2=0 and 3x+4y-10=0

 Linear Simultaneous Equations (Method of Substitution)

Solve the equation 5x+2y+2=0 and 3x+4y-10=0 

Solution :

           5x + 2y + 2 = 0 ....... (equ. 1)

           3x + 4y - 10 = 0 ....... (equ. 2)      

                           (•.• equation 1 and equation 2 are given)

First we mention the equation 1. Here is -

       5x + 2y +2=0

=> 2y = - 5x - 2

=> 2y = -( 5x + 2 )

=> y = - ( 5x + 2 ) / 2 

=> y = - ½ ( 5x + 2 ) ....... (equ. 3)

Now, putting the value of "y" in the equ. 2

=> 3x + 4{- ½ ( 5x + 2 )} - 10 = 0

=> 3x + ² 4{- ½ ( 5x + 2 )} - 10 = 0

=> 3x - 2 ( 5x + 2 ) = 10

=> 3x - 10x - 4 = 10

=> 3x - 10x = 10 + 4

=> -7x = 14

=> x = 14/-7

=> x = ² 14 / - 7

=> x = -2

Now, we have the value of "x".

Once again, Now putting the value of "x" in the equ. 3

=> y = - ½ { 5×(-2) + 2 }

        = - ½ ( -10 + 2 )

        = - ½ ( -8 )

        = -1(-8) / 2

        = 8/2

        = 4

Solution : (x,y) = (-2,4)

                                              Written by : Jayanta Kumar Meher (BSc, BEd)