Answer :
[tex]\bf n^{th}\textit{ term of an arithmetic sequence}\\\\
a_n=a_1+(n-1)d\qquad
\begin{cases}
n=n^{th}\ term\\
a_1=\textit{first term's value}\\
d=\textit{common difference}\\
----------\\
n=76\\
d=4.8\\
a_{76}=375
\end{cases}
\\\\\\
a_{76}=a_1+(76-1)(4.8)\implies 375=a_1+(76-1)(4.8)
\\\\\\
375=a_1+(75)(4.8)\implies 375=a_1+360\implies 15=a_1[/tex]
If the 76th term is 375, one must subtract the common difference n-1 times to get the first term. n is 76 so 375-(75*4.8) which is 15 and we plug 15 into the equation to see if we are right. A(76)=15+(76-1)*4.8 and since we get 375 we are correct.