Question 3
Given , what is the value of ?
(i) 15625 + 126
(ii)
(iii) 15625 + 253
(iv) 15625 + 251
(v)
An algebraic identity helps us find the square of a number easily.
Step 1 — Express the number
We are given the value of . We need to find the value of . We can write as the sum of two numbers. Let us write as .
Step 2 — Apply the identity
We will use a special rule called an algebraic identity. This rule helps us square a sum of two numbers. The identity is . Here, we can think of as . We can think of as . Let us substitute these values into the identity.
We found that is . This matches option (iv).
Answer
(iv)
More questions in FIO
Which of the following numbers are not perfect squares?
(i) 2032 (ii) 2048 (iii) 1027 (iv) 1089
Which one among , , , has last digit 4?
Given , what is the value of ?
(i) 15625 + 126
(ii)
(iii) 15625 + 253
(iv) 15625 + 251
(v)
Find the length of the side of a square whose area is .
Find the smallest square number that is divisible by each of the following numbers: 4, 9, and 10.
Find the smallest number by which 9408 must be multiplied so that the product is a perfect square. Find the square root of the product.
How many numbers lie between the squares of the following numbers?
(i) 16 and 17 (ii) 99 and 100
In the following pattern, fill in the missing numbers:
(a)
(b)
How many tiny squares are there in the following picture? Write the prime factorisation of the number of tiny squares.
Find the cube roots of 27000 and 10648.
What number will you multiply by 1323 to make it a cube number?
State true or false. Explain your reasoning.
(i) The cube of any odd number is even.
(ii) There is no perfect cube that ends with 8.
(iii) The cube of a 2-digit number may be a 3-digit number.
(iv) The cube of a 2-digit number may have seven or more digits.
(v) Cube numbers have an odd number of factors.
You are told that 1331 is a perfect cube. Can you guess without factorisation what its cube root is? Similarly, guess the cube roots of 4913, 12167, and 32768.
Which of the following is the greatest? Explain your reasoning.
(i)
(ii)
(iii)
(iv)