Advertisements
Advertisements
Question
Evaluate the following using identities:
(399)2
Solution
In the given problem, we have to evaluate expressions by using identities.
Given `(399)^2`
We can write`(399)^2 " as " (400 - 1)^2`
We shall use the Identity `(x - y)^2 - 2xy + y^2`
Where x = 400, y = 1
By applying in identity we get
`(400 - 1)^2 = (400)^2 - 2 xx 400 xx 1 + (1)^2`
`= 400 xx 400 - 800 + 1`
= 16000 - 800 + 1
=159201
Hence the value of `(399)^2` is 159201
APPEARS IN
RELATED QUESTIONS
Expand the following, using suitable identity:
(–2x + 5y – 3z)2
Write the following cube in expanded form:
(2a – 3b)3
Simplify the following products:
`(m + n/7)^3 (m - n/7)`
Simplify of the following:
Evaluate:
253 − 753 + 503
If x + y + z = 8 and xy +yz +zx = 20, find the value of x3 + y3 + z3 −3xyz
If a − b = 5 and ab = 12, find the value of a2 + b2
Find the square of `(3a)/(2b) - (2b)/(3a)`.
If a + `1/a`= 6 and a ≠ 0 find :
(i) `a - 1/a (ii) a^2 - 1/a^2`
Use the direct method to evaluate the following products :
(3x – 2y) (2x + y)
Use the direct method to evaluate :
(ab+x2) (ab−x2)
Expand the following:
(x - 3y - 2z)2
Find the squares of the following:
3p - 4q2
Find the squares of the following:
(2a + 3b - 4c)
Evaluate the following without multiplying:
(1005)2
Simplify:
(2x + y)(4x2 - 2xy + y2)
The coefficient of x in the expansion of (x + 3)3 is ______.
Using suitable identity, evaluate the following:
101 × 102
Expand the following:
`(4 - 1/(3x))^3`
Give possible expressions for the length and breadth of the rectangle whose area is given by 4a2 + 4a – 3.
