Nội dung bài giảng
Bài 30 Tìm x, biết
a) \(x : (-\frac{1}{2})^{3} = - \frac{1}{2}\)
b) \((\frac{3}{4})^{5}.x =(\frac{3}{4}) ^{7}\)
Lời giải:
a) \(x : (-\frac{1}{2})^{3} = - \frac{1}{2}\) => x = \((-\frac{1}{2}).(-\frac{1}{2})^{3} = (-\frac{1}{2})^{4} = \frac{1}{16}\)
b) \((\frac{3}{4})^{5}.x =(\frac{3}{4}) ^{7}\) => \((\frac{3}{4})^{7} : (\frac{3}{4})^{5} =(\frac{3}{4})^{2} = \frac{9}{16}\)