Advertisements
Advertisements
प्रश्न
If m – n = 16 and m2 + n2 = 400, then find mn.
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
APPEARS IN
संबंधित प्रश्न
Expand: (98)2
Expand the following square, using suitable identities
(xyz – 1)2
Evaluate the following, using suitable identity
9982
The factors of x2 – 6x + 9 are
Simplify: (a + b)2 – (a – b)2
(a – b)2 + ______ = a2 – b2
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.
p2y2 – 2py + 1
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
4y2 – 12y + 9
Factorise the following.
y2 + 4y – 21
