\(500-\left\{5\left[409-\left(2^3\cdot3-21\right)^2+10^3\right]\right\}:15\)
\(=500-\left\{5\left[409-9+1000\right]\right\}:15\)
\(=500-\left\{5\cdot1400\right\}:15\)
\(=500-7000:15\)
\(=500-\dfrac{1400}{3}\)
\(=\dfrac{100}{3}\)
\(67-\left[8+7\cdot3^2-24:6+\left(9-7\right)^2\right]:15\)
\(=67-\left[8+7\cdot9-24:6+4\right]:15\)
\(=67-\left[8+63-4+4\right]:15\)
\(=67-71:15\)
\(=67-\dfrac{71}{15}\)
\(=\dfrac{934}{15}\)
\(PeaGea\)