Aptitude - Square Root and Cube Root - Discussion
Discussion Forum : Square Root and Cube Root - General Questions (Q.No. 9)
9.
The square root of (7 + 35) (7 - 35) is
Answer: Option
Explanation:
| (7 + 35)(7 - 35) | = | (7)2 - (35)2 | = 49 - 45 = 4 = 2. |
Discussion:
24 comments Page 1 of 3.
Devendra said:
2 years ago
To find the square root of the expression (7 + 3√5) (7 - 3√5), we can simplify it using the difference of squares formula.
Let's denote the expression as A = (7 + 3√5) (7 - 3√5).
Using the difference of squares formula, we have:
A = (7 + 3√5) (7 - 3√5)
= (7)^2 - (3√5)^2,
= 49 - 9(√5)^2,
= 49 - 9(5),
= 49 - 45,
= 4.
Therefore, the √ of (7 + 3√5) (7 - 3√5) is √4 = 2.
Let's denote the expression as A = (7 + 3√5) (7 - 3√5).
Using the difference of squares formula, we have:
A = (7 + 3√5) (7 - 3√5)
= (7)^2 - (3√5)^2,
= 49 - 9(√5)^2,
= 49 - 9(5),
= 49 - 45,
= 4.
Therefore, the √ of (7 + 3√5) (7 - 3√5) is √4 = 2.
(2)
Rafeeq said:
8 years ago
In the question, it is mentioned Square root of....
And the given no is (a+b)(a-b) form. After solving using this formula you will get 4 as the answer. Now note the question, it is mentioned as the square root of. Hence we have to take the whole square root. Hope my answer will be understood by everyone.
And the given no is (a+b)(a-b) form. After solving using this formula you will get 4 as the answer. Now note the question, it is mentioned as the square root of. Hence we have to take the whole square root. Hope my answer will be understood by everyone.
Shilpa sudhan said:
9 years ago
@Joe.
(3R5)^2 = 3 to the power 2 and root 5 to the power 2 root 5 to the power 2 can be written as root 5 into root 5 which is equal to 5 now we get 3^2 * 5 = 45.
(3R5)^2 = 3 to the power 2 and root 5 to the power 2 root 5 to the power 2 can be written as root 5 into root 5 which is equal to 5 now we get 3^2 * 5 = 45.
(1)
Priya said:
7 years ago
@All.
It is mentioned that the square root of (find the square root of a given item), by solving we will get 4. Take the square root of 4 the answer is 2.
It is mentioned that the square root of (find the square root of a given item), by solving we will get 4. Take the square root of 4 the answer is 2.
Jony singla said:
1 decade ago
No answer is 4 because they can't mention square root whole number, they are only mention the square root is root 5 not to 7 or 3.
Ranjith Ragava said:
3 years ago
(7+3√5)(7-3√5).
(a+b)(a-b)=a^2-b^2,
= (7)^2-(3√5)^2,
= (49)-(3^2√5^2),
= 49-(9)(5),
= 49-45,
= 4.
(a+b)(a-b)=a^2-b^2,
= (7)^2-(3√5)^2,
= (49)-(3^2√5^2),
= 49-(9)(5),
= 49-45,
= 4.
(3)
Sreekanth said:
8 years ago
Here square root is already there.
So, a+b * a-b = a2-b2. so, square root a2-b2. So answer is 2 only.
So, a+b * a-b = a2-b2. so, square root a2-b2. So answer is 2 only.
Amu said:
1 decade ago
(a+b)(a-b) = a^2-b^2
So ans must be 4 What is the necessity to take square root?
Please explain me.
So ans must be 4 What is the necessity to take square root?
Please explain me.
Siri said:
1 decade ago
Here square root is already there. so, a+b * a-b = a2-b2. so, square root a2-b2. so answer is 2 only
MANJU said:
1 decade ago
This question is in (a-b)(a+b) form. So we can simplify as a^2-b^2.
So, 7^2 - (9*5) = 49-45 = 4.
So, 7^2 - (9*5) = 49-45 = 4.
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