6*(1\frac{1}{3})^3+8*(1\frac{1}{3})^3-2*(1\frac{1}{3})^3=
wspólny czynnik przed nawias:
(\frac{4}{3})^3*(6+8-2)=\frac{64}{27}*12=\frac{64*4}{9}=\frac{256}{9}=28\frac{4}{9}
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albo:
...=6*(\frac{4}{3})^3+8*(\frac{4}{3})^3-2*(\frac{4}{3})^3=6*\frac{64}{27}+8*\frac{64}{27}-2*\frac{64}{27}=\frac{384+512-128}{27}=\frac{768}{27}=\frac{256}{9}=28\frac{4}{9}