Home
Class 9
MATHS
If 49x^(2)-b=(7x+(1)/(2))(7x-(1)/(2)), t...

If `49x^(2)-b=(7x+(1)/(2))(7x-(1)/(2)),` then the value of b is

A

0

B

`(1)/(sqrt(2))`

C

`(1)/(4)`

D

`(1)/(2)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the equation \( 49x^2 - b = (7x + \frac{1}{2})(7x - \frac{1}{2}) \), we will follow these steps: ### Step 1: Recognize the Identity We can use the identity for the difference of squares: \[ (a + b)(a - b) = a^2 - b^2 \] In our case, let \( a = 7x \) and \( b = \frac{1}{2} \). ### Step 2: Apply the Identity Using the identity, we can rewrite the right-hand side: \[ (7x + \frac{1}{2})(7x - \frac{1}{2}) = (7x)^2 - \left(\frac{1}{2}\right)^2 \] Calculating this gives: \[ (7x)^2 - \left(\frac{1}{2}\right)^2 = 49x^2 - \frac{1}{4} \] ### Step 3: Substitute Back into the Equation Now we substitute this back into the original equation: \[ 49x^2 - b = 49x^2 - \frac{1}{4} \] ### Step 4: Simplify the Equation Next, we can simplify the equation: \[ 49x^2 - b = 49x^2 - \frac{1}{4} \] To isolate \( b \), we can subtract \( 49x^2 \) from both sides: \[ -b = -\frac{1}{4} \] ### Step 5: Solve for \( b \) Now, we multiply both sides by -1 to solve for \( b \): \[ b = \frac{1}{4} \] ### Final Answer Thus, the value of \( b \) is: \[ \boxed{\frac{1}{4}} \]

To solve the equation \( 49x^2 - b = (7x + \frac{1}{2})(7x - \frac{1}{2}) \), we will follow these steps: ### Step 1: Recognize the Identity We can use the identity for the difference of squares: \[ (a + b)(a - b) = a^2 - b^2 \] In our case, let \( a = 7x \) and \( b = \frac{1}{2} \). ...
Promotional Banner

Topper's Solved these Questions

  • POLYNOMIALS

    NCERT EXEMPLAR ENGLISH|Exercise EXERCISE 2.2 very short Answer type Questions|32 Videos
  • POLYNOMIALS

    NCERT EXEMPLAR ENGLISH|Exercise EXERCISE 2.3 very short Answer type Questions|10 Videos
  • NUMBER SYSTEMS

    NCERT EXEMPLAR ENGLISH|Exercise LONG ANSWER TYPE QUESTIONS|7 Videos
  • QUADRILATERALS

    NCERT EXEMPLAR ENGLISH|Exercise LONG ANSWER TYPE QUESTIONS|18 Videos

Similar Questions

Explore conceptually related problems

If 49 a^2-b=(7a+1/2)\ \ (7a-1/2), then the value of b is =? (a) 0 (b) 1/4 (c) 1/(sqrt(2))\ (d) 1/2

If f(x)=(x^(2)+3x+2)(x^(2)-7x+a) and g(x)=(x^(2)-x-12)(x^(2)+5x+b) , then the value of a and b , if (x+1)(x-4) is H.C.F. of f(x) and g(x) is (a) a=10 : b=6 (b) a=4 : b=12 (c) a=12 : b=4 (d) a=6 : b=10

Let x_1 and x_2 be the real roots of the equation x^(2) -kx +(k^(2) +7x+15)=0 if the maximum value of (x_1^(2) + x_2^(2)) is (18)/(x) , then find the value of x .

Solve : (2x)/(3)-(x-1)/(6)+(7x-1)/(4)=2(1)/(6) . Hence, find the value of 'a', if (1)/(a)+5x=8 .

"Let "f(x)=((2^(x)+2^(-x))sin x sqrt(tan^(-1)(x^(2)-x+1)))/((7x^(2)+3x+1)^(3)) . Then find the value of f'(0).

(x^(2)-1)/(x^(2)+7x+1)

If x=(7+5sqrt(2))^(1/3)-1/((7+5sqrt(2))^(1/3)) , then the value of x^3+3x-14 is equal to 1 b. 0 c. 2 d. 4

If y=(x^2-3x+1)/(2x^2-3x+2) , where x is real, the value of y lies between (A) -1leyle5/7 (B) -1/2leyle5/7 (C) 5/7ltylt1 (D) none of these

If x = sqrt(7)+(1)/(sqrt(7)) , then the value of (128)^(x^(2)) is-

If (x^(2) - x - 1)^(x^(2) - 7x + 12) = 1 then