Best Answer

x2 + y2 = x2 - 2xy + y2 + 2xy = (x - y)2 + 2xy = 72 + 2*8 = 49 + 16 = 65

You could, instead, solve the two equations for x and y and substitute, but the above method is simpler.

User Avatar

Wiki User

โˆ™ 2010-01-07 12:29:51
This answer is:
User Avatar
Study guides


20 cards

A polynomial of degree zero is a constant term

The grouping method of factoring can still be used when only some of the terms share a common factor A True B False

The sum or difference of p and q is the of the x-term in the trinomial

A number a power of a variable or a product of the two is a monomial while a polynomial is the of monomials

See all cards
1785 Reviews

Add your answer:

Earn +20 pts
Q: When x-y equals 7 and xy equals 8 find the value of x square plus y square?
Write your answer...
Still have questions?
magnify glass
People also asked