$$Do you mean $\sum_{k=1}^{25}(3k+\frac{1}{4})$?\\ \\ If so, then this can be written as $$3\sum_{k=1}^{25}k+\sum_{k=1}^{25}\frac{1}{4}$$\\\\ This becomes $$3*\frac{25(25+1)}{2}+25*\frac{1}{4}$$\\ $$ = 975+6\frac{1}{4}$$ $$ = 981\frac{1}{4}$$
$$Do you mean $\sum_{k=1}^{25}(3k+\frac{1}{4})$?\\ \\ If so, then this can be written as $$3\sum_{k=1}^{25}k+\sum_{k=1}^{25}\frac{1}{4}$$\\\\ This becomes $$3*\frac{25(25+1)}{2}+25*\frac{1}{4}$$\\ $$ = 975+6\frac{1}{4}$$ $$ = 981\frac{1}{4}$$