Question

Решите задачи по математике !!!

Answer 1

$2.;frac{3^{-10}cdot3^5}{3^{-7}}=frac{3^7cdot3^5}{3^{10}}=3^{7+5-10}=3^2=9\\3.;100%-13%=87%\6960;=;87%\x;=;100%\x=frac{6960cdot100}{87}=8000\\4.;S=frac{d_1d_2sinalpha}2\d_1=frac{2S}{d_2sinalpha}=frac{2cdot27}{18cdotfrac13}=frac{54}6=9$