Welke gelijkheid is correct  ?
A.  a2 − 1 = (a − 1)2
B.   a2 + 1 = (a + 1)(a + 1)
C.  a2 + a  =  a (a + 1)
D.  (a + 1)2 = a2 + 1
E.  a2 − 1 = 1 − a2
                 

[ 1447 - op net sinds 30.3.2020-()-3.11.2021]

Translation in   E N G L I S H

IN CONSTRUCTION
A.  
B.  
C.  
D.  
E.  

Oplossing - Solution

Enkel C is correct (a buiten haken brengen)