$=\frac{413225.85-(\frac{1461.7}{13})^{2}}{12}$
Apply exponent rule $(\frac{a}{b})^{c}=\frac{a^{c}}{b^{c}}$$=\frac{413225.85-\frac{1461.7^{2}}{13^{2}}}{12}$
$\frac{1461.7^{2}}{13^{2}}=\frac{2136566.89}{169}$$=\frac{413225.85-\frac{2136566.89}{169}}{12}$
Divide the numbers: $ \frac{2136566.89}{169}=12642.40763…$$=\frac{413225.85-12642.40763…}{12}$
Subtract the numbers: $ 413225.85-12642.40763…=400583.44236…$$=\frac{400583.44236…}{12}$
Divide the numbers: $ \frac{400583.44236…}{12}=33381.95353…$$=33381.95353…$