Answer:
11 + 6[tex]\sqrt{2}[/tex]
Step-by-step explanation:
(3 + [tex]\sqrt{2}[/tex] )²
= (3 + [tex]\sqrt{2}[/tex] )( 3 + [tex]\sqrt{2}[/tex] )
Each term in the second factor is multiplied by each term in the first factor
= 3( 3 + [tex]\sqrt{2}[/tex] ) + [tex]\sqrt{2}[/tex] ( 3 + [tex]\sqrt{2}[/tex] )
Distribute each parenthesis noting that [tex]\sqrt{2}[/tex] × [tex]\sqrt{2}[/tex] = 2
= 9 + 3[tex]\sqrt{2}[/tex] + 3[tex]\sqrt{2}[/tex] + 2 ← collect like terms
= 11 + 6[tex]\sqrt{2}[/tex]