Question

for the equation 15 x - 12y=69;12x-15y= 39 find the value of ( x+y) & ( x- y ) without actually solving for x &y​

Answer 1

Answer:

15x−12y=69 ...(i)

12x−15y=39 ...(ii)

On adding (i) and (ii) , we get

27x−27y=108

⇒x−y=4

On subtracting (ii) from (i) , we get

3x+3y=30

⇒x+y=10