Advertisements (Quảng cáo)
Tìm x, biết :
a) \(x + {{ – 5} \over {12}} = {3 \over 5}\) ;
b) \( – x – 3 = {5 \over { – 12}}\) ;
c) \(x – \left( {{{ – 4} \over 5} + {1 \over 3}} \right) = {{ – 1} \over 3}\).
Advertisements (Quảng cáo)
\(a)x + {{ – 5} \over {12}} = {3 \over 5} \Rightarrow x = {3 \over 5} – {{ – 5} \over {12}} = {{36} \over {60}} – {{ – 25} \over {60}} = {{61} \over {60}}.\) Vậy \(x = {{61} \over {60}}.\)
\(b) – x – 3 = {5 \over { – 12}} \Rightarrow – x = {{ – 5} \over {12}} + 3 = {{ – 5} \over {12}} + {{36} \over {12}} = {{31} \over {12}} \Rightarrow x = {{ – 31} \over {12}}.\) Vậy \(x = {{ – 31} \over {12}}.\)
\(c)x – \left( {{{ – 4} \over 5} + {1 \over 3}} \right) = {{ – 1} \over 3} \Rightarrow x + {4 \over 5} – {1 \over 3} = {{ – 1} \over 3} \Rightarrow x = {{ – 1} \over 3} + {1 \over 3} – {4 \over 5} \Rightarrow x = {{ – 4} \over 5}.\) Vậy \(x = {{ – 4} \over 5}.\)