12a. First expressing as a fraction, Shan has 12/32 books from his favorite author, so:
12/32=3/8=0.375 books from his favorite author
12b. Because the decimal 0.375 isn't a periodical decimal, so it would be a terminating decimal.
Price after off =80- 1/4 * 80 = 80-20 = $60
Coupon discount = 60*10/100 = $6
So, he have to pay, 60-6 = $54
In your equation: a+(-4)=-13
you then add four to each side,
so a= negative 13 plus 4
so a= -9
to put them together and add them.
I cannot see the picture to good
