বীজগণিতের সূত্রাবলী

$$(a+b)^2 = a^2+2ab+b^2$$

$$(a-b)^2 = a^2-2ab+b^2$$

$$(a+b)^2-2ab = a^2+b^2$$

$$(a-b)^2+2ab = a^2+b^2$$

$$(a+b)^2-4ab = (a-b)^2$$

$$(a-b)^2+4ab = (a+b)^2$$

$$2(a^2+b^2) = (a+b)^2+(a-b)^2$$

$$4ab = (a+b)^2-(a-b)^2$$

$$ab = \left(\frac{a+b}{2}\right)^2 - \left(\frac{a-b}{2}\right)^2$$

$$ab = \frac{(a+b)^2 - (a^2+b^2)}{2}$$

$$ab = \frac{(a^2+b^2) - (a-b)^2}{2}$$

$$(x+a)(x+b) = x^2+(a+b)x+ab$$