Question

if xy=20and(x+y)²=70 then find the value of x²+y²​

Answer 1

Answer:

30

Step-by-step explanation:

expansion of (x+y)^2 = x^2 + y^2 + 2xy

given (x+y)^2 = 70

or, x^2 + y^2 + 2xy = 70

or, x^2 + y^2 + 2 × 20 = 70. { given, xy = 20 }

or, x^2 + y^2 + 40 = 70. { 2× 20 = 40}

or, x^2 + y^2 = 70 - 40

or, x^2 + y^2 = 30

therefore, x^2 + y^2 = 30.

hope this helps...please mark as brainliest