Sagot :
bjr
100
a² = a x a = (√5 - √2) (√5 - √2) = √5x√5 + √5x(-√2) - √2x√5 - √2 x (-√2)
= 5 - √10 - √10 +2
= 7 - 2√10
b² = b x b = (5 + √2) (5 + √2) = 5*5 + 5*√2 + √2*5 + √2²
= 25 + 5√2 + 5√2 + 2
= 27 + 10√2
a² + b² = tu sais additionner..
bjr
100
a² = a x a = (√5 - √2) (√5 - √2) = √5x√5 + √5x(-√2) - √2x√5 - √2 x (-√2)
= 5 - √10 - √10 +2
= 7 - 2√10
b² = b x b = (5 + √2) (5 + √2) = 5*5 + 5*√2 + √2*5 + √2²
= 25 + 5√2 + 5√2 + 2
= 27 + 10√2
a² + b² = tu sais additionner..