Advertisements
Advertisements
प्रश्न
If m – n = 16 and m2 + n2 = 400, then find mn.
बेरीज
Advertisements
उत्तर
Given, m – n = 16 and m2 + n2 = 400.
Since, (m – n)2 = m2 + n2 = 2mn ...[Using the identity, (a – b)2 = a2 + b2 – 2ab]
∴ (16)2 = 400 – 2mn
⇒ 2mn = 400 – (16)2
⇒ 2mn = 400 – 256
⇒ 2mn = 144
⇒ `mn = 144/2`
⇒ mn = 72
shaalaa.com
या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
APPEARS IN
संबंधित प्रश्न
Expand `("x"-2/"x")^2`
(a – 1)2 = a2 – 1
Evaluate the following, using suitable identity
472
Square of 9x – 7xy is ______.
(a – b) ______ = a2 – 2ab + b2
(a – b)2 + ______ = a2 – b2
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
x2 – 10x + 25
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
p2y2 – 2py + 1
Factorise the following.
x2 + 4x – 77
Subtract b(b2 + b – 7) + 5 from 3b2 – 8 and find the value of expression obtained for b = – 3.
