Advertisements
Advertisements
प्रश्न
Using suitable identities, evaluate the following.
9.8 × 10.2
उत्तर
We have,
9.8 × 10.2 = (10 – 0.2)(10 + 0.2)
= 102 – (0.2)2 ...[Using the identity, (a + b)(a – b) = a2 – b2]
= 100 – 0.04
= 99.96
APPEARS IN
संबंधित प्रश्न
Using identity, find the value of (1.9) × (2.1)
The value of p for 512 – 492 = 100p is 2.
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
`x^2/8 - y^2/18`
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
(a – b)2 – (b – c)2
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
(x + y)4 – (x – y)4
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
9x2 – (3y + z)2
Factorise the expressions and divide them as directed:
(x4 – 16) ÷ x3 + 2x2 + 4x + 8
The sum of first n natural numbers is given by the expression `n^2/2 + n/2`. Factorise this expression.
The radius of a circle is 7ab – 7bc – 14ac. Find the circumference of the circle. `(pi = 22/7)`
Verify the following:
(a + b + c)(a2 + b2 + c2 – ab – bc – ca) = a3 + b3 + c3 – 3abc
