F(-1)=5(-1)-1
-5-1
-6
Your answer is-6
12.50 x 8 = 100
100 x 3 = $300
so $275 for 3 months would be the better deal but i’m not sure if by each month u meant 3 months or the whole year. if the whole year was the case it would be
12.50 x 8 = 100
100 x 12 = $1,200
275 x 4 = $1,100
so in that case $275 for 3 months would still be the better deal.
8 1/4
33/4
the opposite is 4/33
[10-11] - [15]
=[21] -[15]
= [6]
anything inside the absolute bracket would have to remain positive, anything outside wouldn't change