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7/12-(5/6-8/9)
=7/12-(15/18-16/18)
=7/12-(-1/18)
=21/36+2/36
=23/36
19/57-5/24
=456/1368-285/1368
=171/1368
=57/456
=19/152
=8
1-1/2+1/4-1/8+1/16
=16/16-8/16+4/16-2/16+1/16
=11/16
=7/12-(15/18-16/18)
=7/12-(-1/18)
=21/36+2/36
=23/36
19/57-5/24
=456/1368-285/1368
=171/1368
=57/456
=19/152
=8
1-1/2+1/4-1/8+1/16
=16/16-8/16+4/16-2/16+1/16
=11/16
A=[tex] \frac{7}{12} [/tex]-([tex] \frac{5}{6} [/tex]-[tex] \frac{8}{9} [/tex])=[tex] \frac{7}{12} [/tex]-(-[tex] \frac{1}{18} [/tex]=[tex] \frac{23}{36} [/tex]
B=[tex] \frac{19}{57} [/tex]-[tex] \frac{5}{24} [/tex]=[tex] \frac{1}{8} [/tex]
C=1-[tex] \frac{1}{2} [/tex]+[tex] \frac{1}{4} [/tex]-[tex] \frac{1}{8} [/tex]+[tex] \frac{1}{16} [/tex]=[tex] \frac{1}{1} [/tex]-([tex] \frac{11}{16} [/tex]=[tex] \frac{5}{16} [/tex]
B=[tex] \frac{19}{57} [/tex]-[tex] \frac{5}{24} [/tex]=[tex] \frac{1}{8} [/tex]
C=1-[tex] \frac{1}{2} [/tex]+[tex] \frac{1}{4} [/tex]-[tex] \frac{1}{8} [/tex]+[tex] \frac{1}{16} [/tex]=[tex] \frac{1}{1} [/tex]-([tex] \frac{11}{16} [/tex]=[tex] \frac{5}{16} [/tex]