Answer:
The maximum number of pounds of potato salad that Charlie can buy is 0.375
Explanation:
see the attached figure to better understand the problem
Let
a ----> the cost of one tuna sandwich
b ----> the cost of a bottle of apple juice
c ----> the cost per pound of potato salad
x ----> pounds of potato salad
we have
![a=\$4.25](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pq14zvjrg2rnec99fduw4ng3gheuerrqdh.png)
![b=\$2.25](https://img.qammunity.org/2020/formulas/mathematics/middle-school/d8lck0pkr2rd9kxgwj4zaafo38qsmvtlue.png)
![c=\$4.00/lb](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b6qyzjr4w032l8t1l3gj8jc2mvk71tiz5w.png)
we know that
He wants to buy a tuna sandwich, a bottle of apple juice, and x pounds of potato salad and can spend up to $8
The inequality that represent this situation is
![a+b+cx \leq 8](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fiyydlel31kdl1mt29ewfbeochtcqlld1n.png)
substitute the given values
![4.25+2.25+4.00x \leq 8](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mtz0vn1gx3fmuf9xygculncb1t48xkv7e5.png)
Solve for x
Combine like terms
![6.50+4.00x \leq 8](https://img.qammunity.org/2020/formulas/mathematics/middle-school/nj8g0umzu8k8678vtcutcq8cj52pd15qcq.png)
Subtract 6.50 both sides
![4.00x \leq 8-6.50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/cnnbi6mippxpytd9w2qbyg6yd813zin2dn.png)
![4.00x \leq 1.50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jia5qjtqr8ctcuqrdbp7eo5n6eja2fkjso.png)
Divide by 4 both sides
![x \leq 1.50/4.00](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kvjp79ukufpbe8miqzyk3v06rsnn07tnxv.png)
![x \leq 0.375\ lbs](https://img.qammunity.org/2020/formulas/mathematics/middle-school/lnlcenf7cm4aea0rq9mvth3rgd21iupypf.png)
therefore
The maximum number of pounds of potato salad that Charlie can buy is 0.375