Find and correct the errors in the following mathematical statement.
(y - 3)2 = y2 - 9
Find and correct the errors in the following mathematical statement.
(z + 5)2 = z2 + 25
Find and correct the errors in the following mathematical statement.
(2a + 3b) (a - b) = 2a2 - 3b2
Find and correct the errors in the following mathematical statement.
(a + 4) (a + 2) = a2 + 8
(a + 4)(a + 2) = a2 + 8
Since (a + 4)(a + 2) = a (a + 4) + 2 (a + 4)
                           = a2 + 4a + 2a + 8
                           = a2 + 6a + 8