Hay gays. I need little help
can yoi gays math this

x² – 2y = 15, x - y = 1

Google it that might work

So don't take my word i'm not exactly a mathematical person but i would assume a. because while selling the soap every month you increase in sells so you would by 11 percent. the you would get the factor 0.89 which if i had to guess would be the monthly profit over 11 probably wrong tho