Question

Formulas of mathematics for 9 class

Answer 1

x+y+z=(x+y+z)2=x2+y2+z2=2xyz+xy+yz+zx

Answer 2

Formulas of mathematics that I know of 9 class:
(x+a)(x+b)= x² +(a+b)x +ab
(a+b)²= a²-2ab+b²
(a+b)² = a²+2ab+b²
a²-b²= (a+b)(a-b)
a³+b³= (a+b)(a²-ab+b²)
a³-b³=(a-b)(a²+ab+b²)
(a+b)³= a³+b³+3ab(a+b)
(a-b)³=a³-b³-3ab(a-b)
(a+b+c)²= a²+b²+c²+2ab+2bc+2ac