Advertisements
Advertisements
प्रश्न
Evaluate: 20.8 × 19.2
बेरीज
उत्तर
20.8 × 19.2
= (20 + 0.8) (20 − 0.8)
= (20)2 − (0.8)2 ......[ ∵ (a − b) (a + b) = a2 − b2]
= 400 − 0.64
= 399.36
shaalaa.com
या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
APPEARS IN
संबंधित प्रश्न
Factorise the following using appropriate identity:
`x^2 - y^2/100`
Expand the following, using suitable identity:
(2x – y + z)2
Simplify the following: 175 x 175 x 2 x 175 x 25 x 25 x 25
Simplify `(x^2 + y^2 - z)^2 - (x^2 - y^2 + z^2)^2`
Simplify of the following:
\[\left( x + \frac{2}{x} \right)^3 + \left( x - \frac{2}{x} \right)^3\]
Evaluate:
\[\left( \frac{1}{2} \right)^3 + \left( \frac{1}{3} \right)^3 - \left( \frac{5}{6} \right)^3\]
If a + b + c = 0, then write the value of \[\frac{a^2}{bc} + \frac{b^2}{ca} + \frac{c^2}{ab}\]
Simplify by using formula :
(x + y - 3) (x + y + 3)
If `"a"^2 - 7"a" + 1` = 0 and a = ≠ 0, find :
`"a"^2 + (1)/"a"^2`
If a2 - 3a - 1 = 0 and a ≠ 0, find : `"a" - (1)/"a"`
