Sunday 31 March 2013

Solve 2x + 3y = 11 and 2x – 4y = – 24 and hence find the value of ‘m’ for which


Solve 2x + 3y = 11 and 2x – 4y = – 24 and hence find the value of ‘m’ for which y =mx + 3.
       2x + 3y= 11                          ... (1)
Subtract 3y both side we get
   2x = 11 – 3y                   … (3)
Plug this value in equation second we get
                        2x – 4y    = –  24                         … (2)
11- 3y – 4y = -  24  
                                         7 y= - 24  – 11
-7y  = - 35
=  - 35 / - 7
y  = 5
Plug this value in equation (3) we get
2x   = 11 – 3* 5
2x   = 11- 15
2x   = - 4
Divide by 2 we get
= - 2
Plug the value of x and y in equation
 y  =mx + 3.
5     = -2m +3
2m  = 3 – 5
   =  - 2 / 2
   =  - 1
Answer x = - 2 , 5 and m = -1

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