Advertisements
Advertisements
Question
Evaluate following using identities:
(a - 0.1) (a + 0.1)
Advertisements
Solution
In the given problem, we have to evaluate expressions by using identities.
The given expression is (a + 0.1)(a - 0.1)
We shall use the identity `(x + y)(x - y) = x^2 - y^2`
Here x = a
y = 0.1
By applying identity we get
`(a + 0.1)(a - 0.1) = (a)^2 - (0.1)^2`
`= (a xx a) - (0.1 xx 0.1)`
`= a^2 - 0.01`
Hence the value of (a + 0.1)(a - 0.1) is `a^2 - 0.01`
APPEARS IN
RELATED QUESTIONS
Factorise:
`2x^2 + y^2 + 8z^2 - 2sqrt2xy + 4sqrt2yz - 8xz`
Write the following cube in expanded form:
(2x + 1)3
Factorise the following:
64a3 – 27b3 – 144a2b + 108ab2
Give possible expression for the length and breadth of the following rectangle, in which their area is given:
| Area : 35y2 + 13y – 12 |
Simplify the following expressions:
`(x^2 - x + 1)^2 - (x^2 + x + 1)^2`
If 3x − 2y = 11 and xy = 12, find the value of 27x3 − 8y3
If a + b = 10 and ab = 16, find the value of a2 − ab + b2 and a2 + ab + b2
If \[x + \frac{1}{x} = 3\] then find the value of \[x^6 + \frac{1}{x^6}\].
If \[a^2 + \frac{1}{a^2} = 102\] , find the value of \[a - \frac{1}{a}\].
If \[x^2 + \frac{1}{x^2} = 102\], then \[x - \frac{1}{x}\] =
Find the square of 2a + b.
Use the direct method to evaluate :
`("z"-2/3)("z"+2/3)`
Evaluate: (5xy − 7) (7xy + 9)
If p + q = 8 and p - q = 4, find:
pq
If x + y = 1 and xy = -12; find:
x2 - y2.
If x + y + z = 12 and xy + yz + zx = 27; find x2 + y2 + z2.
Simplify:
(4x + 5y)2 + (4x - 5y)2
Evaluate the following :
1.81 x 1.81 - 1.81 x 2.19 + 2.19 x 2.19
If a + b + c = 9 and ab + bc + ca = 26, find a2 + b2 + c2.
