Your meal with tax is $49.79 including 9% sales tax. What is the Sales tax amount?

Ithink if im not mistaking b is -3 but im not a 100% sude

A. p = 2(l + w)p/2 - l = ww = p/2 - l b. while isolating the variable w in the equation, i first divided both sides by 2 and then i subtracted l from both sides. i hope this .