[tex]\\ \text{Ms.Gartland bought x number of shirts for the new members of her chorus.}\\ \text{The cost of x shirts, was 77.49 dollars including a }\3.99 \text{ shipping charges}\\ \\ \text{Given that each shirt cost }\$12.25 \text{, so the cost of x shirts would be}\\ =12.25\times x=12.25x\\ \\ \text{hence the equation that represents this situation is:}\\ \\ \text{Total cost of x shirts at a rate of 12.25 dollars each + Shipping charges}=\$77.49\\ \\ \Rightarrow 12.25x+3.99=77.49[/tex]
Hence the equation that can be used to find x is:
12.25 x + 3.99= 77.49
