Question

If x+y = 6 and xy = 8, find x2 + y2

Answer 1

Answer:

Step-by-step explanation:

X is 4 and Y is 2

So 4 square + 2 square

=16+4

=20

Answer 2

If x - y =6 then x = y + 6

Therefore substituting (y + 6) for x xy = 8 becomes y(y + 6) =8

This becomes the quadratic equation y^2 + 6y - 8 = 0

Solving for y using the quadratic formula yields 1.123106 or -7.123106 approx.

If x = y + 6 then x = 7.123106 or -1.123106

x^2 + y^2 = 7.123106^2 + 1.123106^2 = 52 answer

Also x^2 + y^2 = -1.123106^2 + -7.123106^2 = 52 answer