Advertisements
Advertisements
Question
If x – y = 13 and xy = 28, then find x2 + y2.
Advertisements
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
APPEARS IN
RELATED QUESTIONS
Expand (7m − 4)2
Simplify: (a + b)2 – (a – b)2
Square of 9x – 7xy is ______.
Using suitable identities, evaluate the following.
(9.9)2
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
y2 – 14y + 49
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
`x^2/4 - 2x + 4`
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
a2y3 – 2aby2 + b2y
Factorise the following.
x2 – 17x + 60
If m – n = 16 and m2 + n2 = 400, then find mn.
If `x - 1/x = 7` then find the value of `x^2 + 1/x^2`.
