Bài 3:
a: \(=\left(\dfrac{9}{12}-\dfrac{10}{12}\right)^2=\left(-\dfrac{1}{12}\right)^2=\dfrac{1}{144}\)
b: \(=\dfrac{5^8\cdot2^8}{5^{10}\cdot2^{10}}=\dfrac{1}{100}\)
c: \(=\left(\dfrac{72}{24}\right)^2=3^2=9\)
d: \(=\dfrac{2^{42}}{2^{24}}=2^{18}\)
e: \(=\left(-\dfrac{1}{3}\cdot3\right)^7=\left(-1\right)^7=-1\)