sir, 
please explain the elimination method clearly
 

Asked by kamleshsingh826 | 2nd May, 2016, 09:23: PM

Expert Answer:

C o n s i d e r space t h e space s y s t e m space o f space e q u a t i o n s space
x plus 2 y equals negative 1... left parenthesis 1 right parenthesis
a n d
2 x minus 3 y equals 12... left parenthesis 2 right parenthesis
T h e space a b o v e space s y s t e m space h a s space t w o space v a r i a b l e s space x space a n d space y
W e space n e e d space t o space e l i m i n a t e space o n e space o f space t h e space v a r i a b l e space t o space g e t space t h e space v a l u e space o f space t h e space o t h e r space v a r i a b l e.

M u l t i p l y space t h e space e q u a t i o n space left parenthesis 1 right parenthesis space b y space 3 space a n d space e q u a t i o n space left parenthesis 2 right parenthesis space b y space 2 comma space w e space h a v e comma
3 x plus 6 y equals negative 3... left parenthesis 3 right parenthesis
4 x minus 6 y equals 24... left parenthesis 4 right parenthesis
A d d i n g space e q u a t i o n s space left parenthesis 3 right parenthesis space a n d space left parenthesis 4 right parenthesis comma space w e space h a v e comma
7 x equals 21

H e r e comma space w e space h a v e space e l i m i n a t e d space t h e space v a r i a b l e space y space f r o m space t h e space s y s t e m.
T h e space s o l u t i o n space o f space t h e space a b o v e space s y s t e m space i s space
x equals 21 over 7 equals 3
S u b s t i u t i n g space b a c k space t h e space s o l u t i o n space x equals 3 comma space i n space a n y space e q u a t i o n comma space w e space c a n space g e t space t h e space v a l u e space y
T h u s comma space f r o m space e q u a t i o n space left parenthesis 1 right parenthesis comma space w e space h a v e comma
3 plus 2 y equals negative 1
rightwards double arrow 2 y equals negative 4
rightwards double arrow y equals fraction numerator negative 4 over denominator 2 end fraction equals negative 2

Answered by Vimala | 3rd May, 2016, 10:05: AM