Answer:
51 - 10[tex]\sqrt{2}[/tex]
Step-by-step explanation:
( 5[tex]\sqrt{2}[/tex] - 1)² = (5[tex]\sqrt{2}[/tex] - 1)(5[tex]\sqrt{2}[/tex] - 1)
Each term in the second factor is multiplied by each term in the first factor, that is
5[tex]\sqrt{2}[/tex](5[tex]\sqrt{2}[/tex] - 1 ) - 1(5[tex]\sqrt{2}[/tex] - 1 )
Distribute both parenthesis, noting that [tex]\sqrt{2}[/tex] × [tex]\sqrt{2}[/tex] = 2
= 50 - 5[tex]\sqrt{2}[/tex] - 5[tex]\sqrt{2}[/tex] + 1 ← collect like terms
= 51 - 10[tex]\sqrt{2}[/tex]
