Show that the solutions of:

6x + y = 19
3x - 2y = 7

are: x = 3, y = 1


Sagot :

6x + y = 19    eq. 1
3x - 2y = 7     eq. 2

mitiply 
3x - 2y = 7 by 2
6x - 4y=14     eq. 3

equate both eq 1 and eq3

6x + y - 19 = 6x - 4y-14
6x + y - 19 - 6x + 4y+14 = 0
5y - 5 = 0
5y = 5
y = 5/5
y = 1

substitute y to eq. 1
6x + y = 19
6x + 1 = 19
6x = 19 - 1
6x= 18
x = 18/6
x = 3