Advertisements
Advertisements
प्रश्न
If `49x^2 - b = (7x + 1/2)(7x - 1/2)`, then the value of b is ______.
विकल्प
0
`1/sqrt(2)`
`1/4`
`1/2`
Advertisements
उत्तर
If `49x^2 - b = (7x + 1/2)(7x - 1/2)`, then the value of b is `underlinebb(1/4)`.
Explanation:
Given, `(49x^2 - b) = (7x + 1/2)(7x - 1/2)`
⇒ `[49x^2 - (sqrt(b))^2] = [(7x)^2 - (1/2)^2]` ...[Using identity, (a + b)(a – b) = a2 – b2]
⇒ `49x^2 - (sqrt(b))^2 = 49x^2 - (1/2)^2`
⇒ `-(sqrt(b))^2 = -(1/2)^2`
⇒ `(sqrt(b))^2 = (1/2)^2` ...[Multiplying both sides by –1]
∴ `b = 1/4`
APPEARS IN
संबंधित प्रश्न
Evaluate the following product without multiplying directly:
103 × 107
Factorise the following using appropriate identity:
4y2 – 4y + 1
Verify:
x3 + y3 = (x + y) (x2 – xy + y2)
Without actually calculating the cubes, find the value of the following:
(–12)3 + (7)3 + (5)3
Give possible expression for the length and breadth of the following rectangle, in which their area is given:
| Area : 35y2 + 13y – 12 |
Simplify (a + b + c)2 + (a - b + c)2 + (a + b - c)2
Simplify `(x^2 + y^2 - z)^2 - (x^2 - y^2 + z^2)^2`
Find the following product:
Evaluate:
483 − 303 − 183
If x + \[\frac{1}{x}\] = then find the value of \[x^2 + \frac{1}{x^2}\].
If a + b + c = 0, then write the value of \[\frac{a^2}{bc} + \frac{b^2}{ca} + \frac{c^2}{ab}\]
If \[3x + \frac{2}{x} = 7\] , then \[\left( 9 x^2 - \frac{4}{x^2} \right) =\]
Expand the following:
(3x + 4) (2x - 1)
Find the squares of the following:
3p - 4q2
Find the squares of the following:
`(7x)/(9y) - (9y)/(7x)`
Simplify by using formula :
(2x + 3y) (2x - 3y)
If `x + (1)/x = "p", x - (1)/x = "q"`; find the relation between p and q.
Simplify:
`(x - 1/x)(x^2 + 1 + 1/x^2)`
Expand the following:
`(4 - 1/(3x))^3`
If a + b + c = 5 and ab + bc + ca = 10, then prove that a3 + b3 + c3 – 3abc = – 25.
