(x+7)2 = x2 + 2. 7x + 72
= x2 + 14 x + 49
(9 - y )2 = 92 - 2.9y + y2
= 81 - 18y + y2
(z -6)(z+6) = z2 - 62
= z2 - 36
( - x + 2)2 = ( - x ) 2 + 2.(- x ) . 2 + 22
= ( - x )2 + 4(-x) + 4
= x2 - 4x + 4
( - x - 2)2 = ( - x ) 2 - 2.(- x ) . 2 + 22
= ( - x )2 - 4(-x) + 4
= x2 + 4x + 4
( - x + 2 )( - x - 2 ) = ( - x ) 2 - 22
= x2 - 4
-( x + 2)2 = - ( (x + 2 ) 2 )
= - ( x 2 + 4x + 4 )
= - x2 - 4x - 4
-( x - 2)2 = - ( (x - 2 ) 2 )
= - ( x 2 - 4x + 4 )
= - x2 + 4x - 4
-( x + 2)(x-2) = - ( (x + 2 ) (x-2) )
= - ( x 2 - 4 )
= - x2 + 4