evaluate -51^3 in column identity method
Answers
Answer:
Answer
Given number =23
By using column method we have,
∴a=2 and b=3
a
2
(2×a×b) b
2
4 12 9
+1 +0
=5 =12
∴(23)
2
=529
Steps involved in solving column method:
Step 1: Make three columns headed by a
2
,2×a×b and b
2
respectively. Write the values of a
2
,2×a×b and b
2
in columns respectively.
Step 2: In third column underline the unit digits of b
2
i.e 9 and carry the tens digit of it i.e. 0 to the second column and add it to the value of second column is 2×a×b and it will remains 12 if it added to 0.
Step 3: In column second, underline the unit digit of the number obtained in second step i.e. 2 and carry over the ten digit of it to first column and add it to the value of a
2
i.e. 4+1=5
Step 4: Now underline the number obtained in third step in first column i.e. 5. The underlined digits give the required square number.