Advertisements
Advertisements
प्रश्न
Using identity, find the value of (1.9) × (2.1)
Advertisements
उत्तर
(1.9) × (2.1) = (2 – 0.1) × (2 + 0.1)
Substituting a = 2 and b = 0.1 in
(a – b)(a + b) = a2 – b2 we have
(2 – 0.1)(2 + 0.1) = 22 – (0.1)2
(1.9) × (2.1) = 4 – 0.01
(9.9)(2.1) = 3.99
APPEARS IN
संबंधित प्रश्न
Expand: (3x + 4y)(3x - 4y)
(x + 4) and (x – 5) are the factors of ___________
Using the identity (a + b)(a – b) = a2 – b2, find the following product
(p + 2)(p – 2)
The value of p for 512 – 492 = 100p is 2.
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
y4 – 625
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
16x4 – 81
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
(a – b)2 – (b – c)2
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:
(p – q)(p2 + pq + q2) = p3 – q3
