solve for,

Question

Solve 3x+5y=9, 4x+2y=1

Answer 1

The equations are 3x  + 5y  = 9 -------> (1)

4x + 2y  = 1 ----------> (2)

To get two equations that contain opposite terms multiply the first equation by 4 and multiply the second equation by 3.

The resultant equations are

12x + 20y = 36 ---------> (3)

12x + 6y = 3 -------------> (4)

To eliminate x  value subtract equation (4) from (3).

12x + 20y = 36

12x + 6y  = 3

(-)   (-)      (-)

______________

     14y = 33

y = 33/14

Substitute the value of y  = 33/14 in either of the original equations and solve for x.

First equation 3x  + 5y  = 9

3x + 5(33/14) = 9

3x + 165/14 = 9

(42x + 165)/14 =  9

42x  + 165 = 126

42x  = 126 - 165

42x  = - 39

x  = - 39/42

x = - 13/14

Solution x  = - 13/14 and y  = 33/14.