## Elementary Technical Mathematics

$\frac{103}{180}$
Find the least common denominator. Find the prime factorization and eliminate repeated factors. $30=2\times3\times5$ $36=/\!\!\!2\times2\times/\!\!\!3\times3$ LCD=$2\times3\times5\times2\times3=180$ Use the LCD to convert to like fractions. $\frac{29}{36}-\frac{7}{30}=\frac{29\times5}{36\times5}-\frac{7\times6}{30\times6}=\frac{145}{180}-\frac{42}{180}=\frac{145-42}{180}=\frac{103}{180}$