Tìm x, biết:
a) \( x : \left ( - \cfrac{ 1}{2 } \right ) = - \cfrac{1 }{2 } \)
b) \( \left ( \cfrac{ 3}{4 } \right )^5 x = \left ( \cfrac{ 3}{4 } \right )^7 \)
Tìm x, biết:
a) \( x : \left ( - \cfrac{ 1}{2 } \right ) = - \cfrac{1 }{2 } \)
b) \( \left ( \cfrac{ 3}{4 } \right )^5 x = \left ( \cfrac{ 3}{4 } \right )^7 \)