deconstructing
48 : 2 = 24
24 : 2 = 12
12 :2 = 6
6 : 2 = 3
3 : 3 = 1
2 * 2 * 2 * 2 * 3 = 48
...................................
16 : 2 = 8
8 : 2 = 4
4 : 2 = 2
2 : 2 = 1
2 * 2* 2 * 2 = 16
..................................
12 : 2 = 6[tex] \frac{7c}{12} + \frac{5c}{16} = \frac{15}{48} + c \\ \\ \frac{7c*4}{12*4} + \frac{5c*3}{16*3} - \frac{15}{48} = c \\ \\ \frac{28c + 15c}{48} - \frac{15}{48} = c \\ \\ 48c = 43c - 15 \\ \\ 48c - 43c = -15 \\ \\ 5c =- 15 \\ \\ c = -3
[/tex]
6 : 2 = 3
3 : 3 = 1
common denominator 48