Question

(2x+9y)^2
(даю 15 балов)

Answer 1

Ответ:

$\color{blue}{(2x + 9y)}^{2}$

$\color{red}{ {(a + b)}^{2} = {a}^{2} + 2ab + {b}^{2} }$

$\color{blue}{ {(2x)}^{2} + 2 \times 2x \times 9y + {(9y)}^{2} }$

$\color{blue}{ {2}^{2} {x}^{2} + 36xy + {9}^{2} {y}^{2} }$

$\color{blue}{4 {x}^{2} + 36xy + {81y}^{2} }$