Question

If 5x+4y=23 and 4x+5y=22 then what is the value of( x,y)

Answer 1

Explanation:

5x+4y = 23 (i)

4x+5y = (ii)

By subtracting (i) and (ii),

5x+4y = 23

- 4x+5y = 22

______________

= (5x+4y)×4 = 23×4

-(4x+5y)×5 = 22×5

_______________

= 20x+16y = 92

-20x-25y = 110

__________________

0-9y = -18

or -9y = -18

or y = 2

From (i),

5x+4y = 23

or 5x = 15

or x = 15/5 = 3