I need to help to express CA$,$ CP$,$ and CS with respect to CA$0$ and t$.$ someone on chegg answered with the function as I've written on the bottom right part of the picture, but when I tried to plot it on excel with those equation with the $t$ ranging from $0to90$ min, the CP exceeds $100$ mol$/m^3$and the $CS$ becomes a negative value which shouldn't $be$ possible

can anyone point out the mistake and help $me$ with the correct solution $(i\text{'}ve$ checked the excel function more than $20$ times and $am100\%$ sure ther $isno$ typos $or$ miswritings with the cells $or$ functions$)$