Question

$sqrt{x-7}=13-x$

Answer 1

$sqrt{x-7}=13-x\ sqrt{x-7} geq 0= textgreater 13-x geq 0\13-x geq 0\x leq 13\\( sqrt{x-7})^2=(13-x)^2\x-7=169+x^2-26x\x^2-27x+176=0\D=(-27)^2-4*1*176=729-704=25=5^2\x_1=(27+5)/2=32/2=16( textgreater 13)\x_2=(27-5)/2=22/2=11( textless 13)$

Ответ: 11