Question

Solve 9x-4y=2000 7x-3y=2000 by using substitution method please help me fast

Answer 1

9x-4y=2000
or,9x=2000+4y
or, x=(2000+4y)/9
7x-3y=2000
or,7[(2000+4y)/9]-3y=2000
or,(14000+28y)/9-3y=2000
or, (14000+28y-27y)/9=2000
or, 14000+y=2000*9
or, y=18000-14000
or, y=4000
then x=(2000+4y)/9=(2000+4*4000)/9=(2000+16000)/9=18000/9=2000
the required solution is: x=2000, y=4000

Answer 2

Answer:

MULTIPLY EQUATION 1 BY 7 & EQUATION 2 BY 9

7(9x-4y=2000)---1

9(7x-3y=2000)----2

63x-28y=14000---3

63x-27y=18000---4

- + -

0 -y = -4000

THEREFORE Y =4000

PUT 4000 IN EQUATION 1

9x -16000=2000

THEREFORE x=2000

HOPE THIS HELPS