1. Binomische Formel: $(a+b{)}^2=a^2+2ab+b_{}^2(a+b)^2=a^2+2ab+b\_\{\; \}^2$

Vergleiche die Terme

$b=\sqrt{9y^2}=3yb=\backslash sqrt\{9y^2\}=3y$

$2ab=2x\cdot 3y=12xy2ab=2x\backslash cdot\; 3y=12xy$

$(2x+3y{)}^2=4x^2+12xy+9y^2(2x+3y)^2=4x^2+12xy+9y^2$