How do you solve the following linear system: x+y=1, 2x-3y=12x+y=1,2x3y=12?

1 Answer
Mar 20, 2018

x= 3 and y = -2x=3andy=2

Explanation:

Let x+y=1x+y=1 ----------equation (1),

and 2x-3y=122x3y=12 -----------equation (2).

Multiply equation (1) by 2 and subtract the resultant equation from (2). This is eliminate one variable, i.e. xx and we will get value of yy. Then substitute the obtained value of yy in any one original given equation to get value of xx:

(1) times 2 ×2 - (2) =>(2)

=> 2x +2y - (2x -3y) = 2- 122x+2y(2x3y)=212

=> 2x +2y -2x +3y = -102x+2y2x+3y=10

=> 5y = -105y=10

=> y = -2y=2

Substituting yy in (1)

(1) => x + (-2) = 1x+(2)=1

=> x = 1+2 =3 x=1+2=3

therefore x= 3 and y = -2