Question

if (x-y)= 13 and xy=-5 then find the value of 1/3 x^2+y^2​

Answer 1

Answer:

Step-by-step explanation:

x + y = 13 ……(1)

xy = 25/4 …..(2)

(x - y)² = (x + y)² - 4 xy = (13)² - 4 × 25/4

=169 - 25 = 144

(x - y) = 12 …….(3)

From the equation (1) and (3)

x + y = 13

x - y = 12

Adding the equations, we get

2x = 25

or x = 25/2 and substituting the value of x in equation (1), we get

25/2 + y = 13

or y = 13 - 25/2 = (26 - 25)/2 = 1/2