A number or expression multiplied by itself can be written as a square, that is a power with the exponent 2.2.2. 3⋅3=32x⋅x=x2(a+b)(a+b)=(a+b)2\begin{aligned} 3\cdot 3 &= 3^2\\ x \cdot x &= x^2 \\ (a+b)(a+b) &= (a+b)^2 \end{aligned}3⋅3x⋅x(a+b)(a+b)=32=x2=(a+b)2