Algebra important formulas

Remember always

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

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

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

(a+b)^3= a^3+b^3+3ab(a+b)

 (a-b)^3= a^3-b^3-3ab(a-b)

 a^3+b^3=(a+b)(a^2+b^2-ab)

a^3-b^3=(a-b)(a^2+b^2+ab)

 (a+b)^2= (a-b)^2+4ab

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

 (a+b+c)^2=a^2+b^2+c^2+2ab+2bc+2ac

(a-b+c)^2=a^2+b^2+c^2-2ab-2bc+2ac

(a-b-c)^2=a^2+b^2+c^2-2ab+2bc-2ac

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

Product of two numbers=  Their LCM   X  Their  HCF