Question

A1/72+1/60
B)1/72-1/60
C)7/72-5/60
D)11/45-1/36+1/12

Answer 1

MMC (Menor Múltiplo Comum)

a) $\frac{1}{72} + \frac{1}{60}=$
72 60 | 2    MMC
36 30 | 2
18 15 | 2
 9 15  | 3
 3   5 |  3
 1  5  | 5   $2^{3} * 3^{2} *5= 360$
 1  1

 $\frac{1}{72} + \frac{1}{60}= \frac{5+6}{360}= \frac{11}{360}$

$\frac{1}{72} - \frac{1}{60}$

$\frac{1}{72} - \frac{1}{60}= \frac{5-6}{360}= \frac{-1}{360}$

$\frac{7}{72} - \frac{5}{60}$

$\frac{7}{72} - \frac{5}{60}= \frac{35-30}{360}= \frac{5}{360}= \frac{1}{72}$

$\frac{11}{45} - \frac{1}{36} + \frac{1}{12}$

MMC 45, 36,12 = 180

$\frac{44-5+15}{180} = \frac{54}{180} = \frac{3}{10}$