Answer:
What Wally did wrong is that it is supposed to be (4a-5)(a-4)
In order to get -21 a. He was supposed to use negative 5 and 4 to get to negative 21
If he used (4a+5)(a+5)
The answer will be positive 21 and that's not what the problem is asking
Step-by-step explanation:
Hope this helps :)
-14
difference between -20 and -5 = 15
15 x 2/5 = 30/5 = 6
-20 + 6 = -14
