(– 9 – 5x) (5x + 9)
is gelijk aan
A. 25x
2
– 90x + 81
B. – 90x
C. –25x
2
– 81 – 90x
D. –(9 – 5x)
2
E. –25x2 + 90x – 81
[ 2-9723 - op net sinds 3.1.2025-(E)- ]
Translation in E N G L I S H
(– 9 – 5x) (5x + 9) =
Oplossing - Solution
(– 9 – 5x) (5x + 9) = −(5x + 9)(5x + 9)= −(5x + 9)
2
= −(25x
2
2.5x.9 + 9
2
) = −25x
2
− 90x − 81
