Simplification of Expressions

Order of Operations in Maths...#PEMDAS
BODMAS

1.Parenthesis i.e Bracket(),[],{} first
From innermost to outer

2. Exponent i.e power (like square)

3. Multiplication & Division (left to right)

4. Addition & Substraction (left to right)

5.Distribute when brackets exist.
Example:
2(x + y) + 3(x - y)
= 2x + 2y + 3x - 3y
= 5x - y

Example #order of operations...

Eg. 1: 6+(14-3)×5-5²+22÷2=??
Ans:-
Solve Bracket first,
=6+(11)×5-5²+22÷2
Now,Exponent
=6+11×5-25+22÷2
Now,Multiply&Divide from left to right,
=6+55-25+11
Now, Addition & Subtraction from left to right,
=61-25+11
=36+11
=47...!

Divisibility Rules 👆

Important formulas

1. a³+b³+c³-3abc = (a+b+c)(a²+b²+c²-ab-bc-ca)

2. (a+b)³= a³+3a²b+3ab²+b³

3. a³+b³= (a+b)(a²-ab+b²)

4. a³-b³= (a-b)(a²+ab+b²)

5. (a+b+c)²= a²+b²+c²+2ab+2bc+2ca

6. (a+b)²= a²+2ab+b²

7. (a-b)²= a²-2ab+b²

8. a²-b²= (a-b)(a+b)
...

You should know the tables from 1-25...!

Assuming that, We know square of each number from 1-25. We are going to find square of of any number bigger than 25. By assuming base as 50, 100, 150, 200, 250, 300......

Base 50 : i.e for numbers between 26-75.
1. Get the difference between 50 and given number and square it(Write it on right side such that it will consume last two digits.
2. Subtract the difference( if number < 50) or Add the difference (if number > 50) in 25. And Write result in front of result of case 1.

e.g (46)^2 = (25-4)=21 and (4^2)=16 i.e 2116

Same for 57^2 = (25+7) and (7^2)
i.e 3249

Base 100 : i.e for numbers between 76-125.
1. Get the difference between 100 and given number and square diff(Write it on right side such that it will consume last two digits and carry 100th digit if 3digits are there.
2. Subtract the difference( if number < 100) or Add the difference (if number > 100) in given number And Write result in front of result of case 1.

Example 1: 104 × 104
diff- 4... Square - 16
104+4=108
Answer: 10816

Example 2: 97 × 97
Case1- Diff- 3 square 09
Case2- 97-3 = 94
Concate case1 and case2
Answer: 9409

By using this trick you can find square of any numbers between 51-150... Practice accordingly

Base 150 : i.e for numbers between 126-175.
1. Get the difference between 150 and given number and square diff(Write it on right side such that it will consume last two digits and carry 100th digit.
2. Subtract the difference( if number < 150) or Add the difference (if number > 150) in given number and multiple the number by 1.5. And Write result in front of result of case 1.

e.g: 1. 160×160
Case1- diff- 10-square- 100
Add diff- 160+10=170
Multiply by 1.5- 170×1.5=255
Concate 255 and 100 carry 100th position
Ans: 25600

E.g 136×136
Diff- 14- square - 196
Substarct 14 from 136= 122
122×1.5 = 183
Concate 183 and 196 such that 1 will carry
Ans: 18496

Understand the difference when you find it with calculations and by TRICK given above.

Base 200 : i.e for numbers between 175-225.
1. Get the difference between 200 and given number and square diff(Write it on right side such that it will consume last two digits and carry 100th digit.
2. Subtract the difference( if number < 200) or Add the difference (if number > 200) in given number and multiple the number by 12. And Write result in front of result of case 1.

e.g: 1. 212
Case1- diff- 12-square- 144
Add diff- 212+12=224
Multiply by 2: 224×2=448
Concate 448 and 144 carry 100th position
Ans: 44944

E.g 176×176
Diff- 24- square - 576
Substarct 24 from 176 = 152
152×2 = 304
Concate 304 and 576 such that 5 will carry
Ans: 30976

I think you can now easily find the squares of any number by understanding the above shortcuts. From tomorrow onwards, we will start learning how to identify whether a number is a perfect square or not, along with the rules for it.
Excited?

Here, we find square of number 212 which is 44944.
This form of number are called palindrome that is from middle they are at same distance on both the sides and similar also.