Найди значение выражений -7/12n-1 если n=-1 ; 3/7 ; -0,84

Условие можно прочитать по-разному:
1)
$- \frac{7}{12} n - 1 \\ \\ n=-1 \\ - \frac{7}{12} *(-1) - 1 = \frac{7}{12} - 1 = - \frac{5}{12} \\ \\ n= \frac{3}{7} \\ - \frac{7}{12} * \frac{3}{7} - 1 = - \frac{1}{4} -1 = -(0.25 + 1) = - 1.25 \\ \\ n=-0.84 \\ - \frac{7}{12} *(-0.84) - 1 = - \frac{7}{12} *(- \frac{21}{25} ) - 1= \frac{7*7}{4*25} -1= -1 +0.49=-0.51$

2)
$- \frac{7}{12n} - 1 \\ \\ n= -1 \\ - \frac{7}{12*(-1)} - 1 = - (- \frac{7}{12} ) - 1 = \frac{7}{12} -1 = - \frac{5}{12} \\ \\ n= \frac{3}{7} \\ - \frac{7}{12* \frac{3}{7} } - 1 = -7 : \frac{36}{7} -1 = - \frac{7}{1} * \frac{7}{36} -1=- (1 \frac{13}{36} +1)= -2 \frac{13}{36} \\ \\ n=-0.84 \\ - \frac{7}{12*(-0.84)} - 1 = -7 : (-10,08) - 1 = \frac{7*25}{1*252} -1 = \frac{25}{36} -1= - \frac{11}{36}$

3)
$- \frac{7}{12n-1} \\ \\ n=-1 \\ - \frac{7}{12*(-1) -1}= - \frac{7}{-12-1} =- (- \frac{7}{13} )= \frac{7}{13} \\ \\ n= \frac{3}{7} \\ - \frac{7}{12* \frac{3}{7}-1}= - \frac{7}{ \frac{29}{7} } = - \frac{7}{1} * \frac{7}{29} = - \frac{49}{29}=-1 \frac{20}{29} \\ \\ n= -0.84 \\ - \frac{7}{12*(-0.84) -1 } = - \frac{7}{-10.08-1} = -(- \frac{7}{11,08} )= \frac{700}{1108} = \frac{175}{277}$