Answer:
13
Step-by-step explanation:
If he read 9 books in january and read 4 more in july than he did in january then he read 13 books in july.
The numbers are irrational, so they can't be exactly written down
using only digits.
In exact form, they are
1 + √57
and
1 - √57 .
In rounded form, they are
8.54983
and
-6.54983 .
1a:
580 - (580 × .1) - 20
580 - (58) - 20
522 - 20
502
1b:
990 - (990 × .25) - 20
990 - (247.5) - 20
742.5 - 20
722.5
I'm not sure how to solve #2.
So x equals two if it is an exponent.9