Math, asked by kumarnjnk, 10 months ago

Find the value of a if

√5+2√3 / 7+4√3
= a 6√3 .​

Answers

Answered by nikkki47
1

Answer:

Lhs = (5+2√3)/(7+4√3)

= [(5+2√3)(7-4√3)]/[(7-4√3)(7+4√3)]

=[35-20√3+14√3-24]/[7²-(4√3)²]

=[11-6√3]/[49-48]

=11-6√3

therefore

11-6√3 = a+b√3

compare both sides

a= 11, b= -6

Step-by-step explanation:

give me branilest

Answered by praveensf25
0

Answer:

Answer: a=11, b=-6

Solution:

Given (5 + 2√3)/(7 + 4√3) = a + b√3

Rationalizing the denominator on left-hand-side by multiplying the numerator and denominator with (7 - 4√3),

(5 + 2√3) (7 - 4√3)/(7 + 4√3) (7 - 4√3) = a + b√3

Multiply term by term the two expressions on numerator of L.H.S. and for the denominator apply the identity (m+n) (m-n) = m² - n² . We obtain,

(35 - 20√3 + 14√3 - 8.√3.√3)/[7² - (4√3)²] = a + b√3

Or, (35 - 6√3 - 8.3)/(49 - 48) = a + b√3

Or, (35 - 6√3 - 24)/1 = a + b√3

Or, 11 - 6√3 = a + b√3

Now equate the rational and irrational terms from both sides.

11 = a

Or, a = 11

- 6√3 = b√3

⇒ b = -6

Verification:

To prove (5 + 2√3)/(7 + 4√3) = a + b√3

i.e. to prove (5 + 2√3) = (a + b√3) (7 + 4√3)

Substituting for a=11 and b=-6,

R.H.S.= (a + b√3) (7 + 4√3)

= (11 - 6√3) (7 + 4√3) = 11.7 + 11.4√3 - 6√3.7 - 6.4.√3.√3 = 77 + 44√3 - 42√3 - 24.3

= 77 + 2√3 - 72 = 5 + 2√3 = L.H.S.

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Solving the LHS,

(5+2√3)/(7+4√3).

Here, since the denominator is not a rational number, we can rationalise it for our ease by multiplying (7–4√3) with the numerator as well as denominator such that we form (a+b)*(a-b) which would be same as a²-b² which is a popular identity.

After multiplying, we would get

(5+2√3)*(7–4√3)/(49–48)=(35–20√3+14√3–24)/1

=11–6√3 or 11+(-6)√3.

Comparing it to RHS , we get a=11 and b=-6.

Thank you.

First simplify (5+2√3)/(7+4√3)

=((5+2√3)(7–4√3))/(7^2-(4√3)^2)

=(35+14√3–20√3–24)/(49–48)

=11–6√3

Now,

(5+2√3)/(7+4√3)=a+b√3

Or,11–6√3=a+b√3

Therefore a=11 & b=-6.

What is the value of a and b, if (3+√5) / (3-√5) =a+b√5 where a and b are rational numbers?

What is the answer of simplify 7+3√5\3+√5+7-3√5\3-√5?

What will be value of √ (-√3+√ (3+8√ (7+4√3)))?

(5+2√3)/(7+4√3)=a+b√3

Rationalising the denominator gives

(5+2√3)(7–4√3)/{(7+4√3)(7–4√3)}=a+b√3

➝{5× (7-4√3)+2√3 ×(7-4√3)}/{ 49–48}=a+b√3

{5×7-5×4√3+7× 2√3-2 √3×4√3}=a+b √ 3

35-20√3+14√3-24=a+b√3

➝11- 6√3=a+b√3

Hence a=11

and b√3=-6√3

Hence b=-6

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Multiplying in Nr and Dr by (7–4√3)

(5+2√3)×(7–4√3)/(7+4√3)×(7–4√3)= a+b√3

or. (35–6√3–24)/(49–48) = a+b√3

or. 11–6√3 = a+b√3

Comparing the both sides.

a=11. and b= -6. Answer.

5 + 2√3/7 + 4√3 = a + b√3

=> (35 + 2√3 +28√3) /7 = a + b√3

=> 35 + 30√3 = 7a + 7b√3

By equating coefficients

7a = 35

=> a = 5

& 7b = 30

=> b = 30/7

Namaskar…. Kaisa hal chaal?? Hi how r u?

Hola como estas?

So,

a = 11 and b = -6.

I hope this ans. is satisfying. I left a few calculation purposely. I feel if you are doing bits of calculation in your brain then you are engaging your brain to do something plus I didnt want to spoonfeed every lil detail.

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