Question

x+y =5 and xy=-1 then X² +y² is
a. 27
b. 22
c. 12
d. 20

Answer 1

Answer:

x^2+y^2 =23.

Given:

x + y =5

xy = -1

To Find:

X² +y²

Step-by-step explanation:

X+y=5 and xy=1

(X+y) ^2=x^2+y^2+2*X*y

5^2=x^+y^2+2*1

25=x^2+y^2+2

25-2=x^2+y^2

23=x^2+y^2

therefore x^2+y^2 =23.