Question

find the value of (x²+y²), if x+y=10and xy=15​

Answer 1

Step-by-step explanation:

lets take the second equation

xy=15

y=15/x

put the new value of y in first equation

x + 15/x = 10

x + 15 = 10x

15 = 10x - x

15 = 9x

x = 15/9

x = 5/3

x= 1.66

so the value of y will be

1.66 + y = 10

y = 10 - 1.66

y = 8.33

therefore

x²+y²

1.66² + 8.33²

2.7556 + 69.3889

72.1445

or , 72 289/2000

Answer 2

lets take the second equation

xy=15

y=15/x

put the new value of y in first equation

x + 15/x = 10

x + 15 = 10x

15 = 10x - x

15 = 9x

x = 15/9

x = 5/3

x= 1.66

so the value of y will be

1.66 + y = 10

y = 10 - 1.66

y = 8.33

therefore

x²+y²

1.66² + 8.33²

2.7556 + 69.3889

72.1445

or , 72 289/2000