Simple,
writing out the problem...

Simplify it...
-4x(6+5-1)
-4x(11-1)
-4x(10)
-40x
Making it look like...

Cancel out the common factors...
Thus making the answer:

.
Answer:
432 pages.
Step-by-step explanation:
We know Madison reads 24pgs/ per day. She reads for nine days, so she reads 24*9 pages, or 216.
We know also that this is halfway through her book, so 2*216= the whole book, so the book has 432 pages
What you can do is multiply 400*20= 8,000. From here, we know that 399*20 is just one less group of 20 than 400. Therefore, we can subtract (1*20) from 8,000 to get the final answer.
8000-20=7980
Hope this helps!
26. 4 people went to the aquarium
27. $1.50 per game (subtraction property and division property)