Advertisements
Advertisements
Question
If x – y = 13 and xy = 28, then find x2 + y2.
Sum
Solution
Given, x – y = 13 and xy = 28
Since, (x – y)2 = x2 + y2 – 2xy ...[Using the identity, (a – b)2 = a2 + b2 – 2ab]
∴ (13)2 = x2 + y2 – 2 × 28
⇒ x2 + y2 = (13)2 + 56
⇒ x2 + y2 = 169 + 56
⇒ x2 + y2 = 225
shaalaa.com
Is there an error in this question or solution?
APPEARS IN
RELATED QUESTIONS
Expand `("x"-2/"x")^2`
Expand: (5x - 4)2
Expand the following square, using suitable identities
(xyz – 1)2
Square of 9x – 7xy is ______.
(a – b) ______ = a2 – 2ab + b2
Factorised form of 4y2 – 12y + 9 is ______.
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
x2 – 8x + 16
Verify the following:
(a – b)(a – b)(a – b) = a3 – 3a2b + 3ab2 – b3
Subtract b(b2 + b – 7) + 5 from 3b2 – 8 and find the value of expression obtained for b = – 3.
If `x - 1/x = 7` then find the value of `x^2 + 1/x^2`.
