Question

irrelevant answers will be report​

Answer 1

Answer:

$using \: formula \: ( {a + b)}^{2}$

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

$9 {a}^{2} + 12ab + 4 {b}^{2}$

Answer 2

hey mate!

19) ( 3a + 2b )²

= ( 3a )² + 2 × 3a × 2b + ( 2b )²

= 9a² + 12ab + 4b²

20) 10xy + 14x + 15y + 21

= 2x ( 5y + 7 ) + 3 ( 5y + 7 )

= (5y + 7) (2x + 3)

hope this helps you

pls mark it as brain list

thanks❤❤