If a = ?3/2, then ?1 + a + ?1 - a =?

Let us assume
P = ?1 + a + ?1 - a
Square on both side,
P ² = ( ?1 + a + ?1 - a ) ²
Use the formula ( a + b ) ² = a ² + b ² + 2ab
we will get
? P ² = (1 + a) + (1- a) + 2 ?1 + a x ?1 - a
? P ² = (1 + a) + (1- a) + 2 ?(1 + a ) x ( 1 - a )
? P ² = 2 + 2 ?1 - a²
? P ² = 2 (1 + ?1 - a²)
Now put the value of a which is given in question;
? P ² = 2 (1 + ?1 - ( ?3/2 )²)
? P ² = 2(1 + ?1 - 3/4 )
? P ² = 2(1 + ?1/4 )
? P ² = 2(1 + 1/2) = 2 x 3/2 = 3
? P= ?3
? (?1 + a + ?1 - a) = ?3