Question

if x+y=22, x^2+y^2=370 find xy

Answer 1

Answer:

(x2+y2)2=xy

x4+2x2y2+y4−xy=0

Differentiating w.r.t x, 

4x3+2[x2.2y $\frac{dy}{dx}$+y2(2x)]+4y3

Answer 2

Step-by-step explanation:

GIVEN

x + y = 22

x² + y² = 370

We know that

(a + b)² = a² + b² + 2ab

SOLUTION

(x + y) = x² + y² + 2xy

22 = 370 + 2xy

2xy = 22 - 370

2xy = - 348

xy = - 174