Question

Решите систему уравнений

Answer 1

$left { {{7^{x-1}(7+1) geq 56} atop {5^{-x}*5^2 textgreater 5^{-x^2}}} right. \\ left { {{7^{x-1} geq 7} atop {5^{2-x} textgreater 5^{-x^2}}} right. \\ left { {{x-1 geq 1} atop {2-x textgreater -x^2}} right. \\ left { {{x geq 2} atop {x^2-x+2 textgreater 0}} right. \\ D=1-8 textless 0= textgreater xin R\\ OTBET:xin[2;+infty)$