Advertisements
Advertisements
प्रश्न
Evaluate: 20.8 × 19.2
बेरीज
Advertisements
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:
`2x^2 + y^2 + 8z^2 - 2sqrt2xy + 4sqrt2yz - 8xz`
Write in the expanded form: (-2x + 3y + 2z)2
Find the following product:
\[\left( 3 + \frac{5}{x} \right) \left( 9 - \frac{15}{x} + \frac{25}{x^2} \right)\]
If a + b = 8 and ab = 6, find the value of a3 + b3
If a + b + c = 9 and ab + bc + ca = 23, then a2 + b2 + c2 =
Use identities to evaluate : (998)2
If 3x + 4y = 16 and xy = 4, find the value of 9x2 + 16y2.
Find the squares of the following:
`(7x)/(9y) - (9y)/(7x)`
Simplify:
(2x + y)(4x2 - 2xy + y2)
If a + b + c = 9 and ab + bc + ca = 26, find a2 + b2 + c2.
