Question

109. If x and y are two integers such that
vxy = 10, then the value of ( x + y )
cannot be​

Answer 1

Answer:

x + y can not lie between -20  & 20

Step-by-step explanation:

Let say  x + y  = a

√xy = 10

Squaring both sides

xy = 100

=> y = 100/x

=> x + 100/x = a

=> x² + 100 = ax

=> x² - ax + 100  = 0

=> x =  (a ± √(a² - 400)) /2

a² - 400 ≥ 0

=> a² ≥ 400

=>      a ≥20 or a ≤ - 20

so    a can not lie between -20  & 20

=> x + y can not lie between -20  & 20