বীজগাণিতিক সূত্রসমূহ

 

1.☞ (a+b)²= a²+2ab+b²

2.☞ (a-b)²= a²-2ab+b²

3.☞ a²-b²= (a +b)(a -b)

4.☞ (a+b)²= (a-b)²+4ab

5.☞ (a-b)²= (a+b)²-4ab

6.☞ a² + b²= (a+b)²-2ab.

7.☞ a² + b²= (a-b)²+2ab.

8.☞ 2(a²+b²)= (a+b)²+(a-b)²

9.☞ 4ab = (a+b)²-(a-b)²

10.☞ ab = {(a+b)/2}²-{(a-b)/2}²

11.☞ (a+b+c)² = a²+b²+c²+2(ab+bc+ca)

12.☞ 2(ab+bc+ca)= (a²+b²+c²)-(a+b+c)²

13.☞ (a²+b²+c²) = (a+b+c)²-2(ab+bc+ca)