The square root for 732 - 552 is:
- AOption (a)
42
- BOption (b)
48
- COption (c)
18
- DOption (d)
52
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Correct answer
48
Why this answer is correct
Shortcut Trick
To find the square root of the difference of two squares, apply the identity a2 − b2 = (a + b)(a − b).
√(732 − 552) = √((73 + 55) × (73 − 55))
⇒ √(128 × 18) = √(2304)
Since 402 = 1600 and 502 = 2500, and the number ends in 4, the answer must be 48.
∴ The correct answer is 48.
Alternate Method
Given: Expression = √(732 − 552)
Formula Used: algebraic identity a2 − b2 = (a + b)(a − b)
⇒ Expression = √((73 + 55) × (73 − 55))
⇒ Expression = √(128 × 18)
⇒ Expression = √(64 × 2 × 2 × 9)
⇒ Expression = √(64 × 4 × 9)
⇒ Expression = 8 × 2 × 3
⇒ Expression = 48
∴ The correct answer is 48.
Additional Information
Algebraic Identities
The formula a2 − b2 = (a − b)(a + b) is one of the most common algebraic identities used to simplify products and square roots of differences.
Square root of a product
The property √(x × y) = √x × √y allows breaking down large products into smaller perfect squares for easier calculation.
Units Digit Rule
A perfect square ending in 4 must have a square root ending in either 2 or 8 (since 22=4 and 82=64).















