12:
a: =3/4(37+1/2-13-1/2)
=24*3/4=18
b: \(=\dfrac{15}{34}+\dfrac{9}{34}-1-\dfrac{15}{17}+\dfrac{1}{3}+\dfrac{2}{3}\)
=24/34-15/17
=12/17-15/17=-3/17
c: \(=\dfrac{-5}{3}\left(16+\dfrac{2}{7}-28-\dfrac{2}{7}\right)=-12\cdot\dfrac{-5}{3}=20\)
d: \(=25\cdot\dfrac{-1}{27}+\dfrac{1}{5}-2\cdot\dfrac{1}{4}-\dfrac{1}{2}\)
=-25/27+1/5-1
=-25/27-4/5
=-125/135-108/135=-233/135
e: =3^12/3^11=3
f: \(=\left\{\left[\left(\dfrac{1}{2}-\dfrac{1}{8}\right)^2\cdot\dfrac{4^2}{3^3}\right]:\left(\dfrac{1}{12}\right)^2\right\}-\dfrac{-5}{6}\)
\(=\left\{\left[\dfrac{3^2}{8^2}\cdot\dfrac{4^2}{3^3}\right]\cdot144\right\}+\dfrac{5}{6}\)
\(=12+\dfrac{5}{6}=\dfrac{77}{6}\)