Tính: a) (x + 5) . (x + 5); b) (x + 1) . (x - 2)

3. Tính
a ,( x + 5 ) . ( x + 5 )
b , ( x + 1 ) .( x - 2 )
c , ( y - 2 ) . ( y + 4 )
d , ( x - 4 ) . ( x - 4 )