Question

If (x-y)=5 and xy=24, find (x+y)​

Answer 1

Step-by-step explanation:

x-y= 5....(i). xy=24....(ii)

x= y+5

[ apply x=y+5 in (ii) no. equation]

so, xy=24

(y+5)y= 24

y²+5y=24

y²+5y-24=0

y² + (8-3)y- 24=0

y²+8y-3y-24=0

y(y+8)- 3(y+8)=0

(y+8) ( y- 3 )= 0

therefore,

(y+8)=0 ( y -3)=0

y= -8 y= +3

We take, y=3 because it has '+' sign and it apply to equation no. (i)

x -y=5

x- 3 = 5

x=5+3

x=8

Therefore, x=8 and y=3

so, x+y= 8+3 =11 (ans)