Решить уравнение
72/(х+5) + 54/(х-5)=9

(72(x-5) +54(x+5)) /(x² -25) =972x -360 +54x +270 =9(x² -25)126x -90 -9x² +225 =0-9x² +126x +135 =0; :(-9)x² -14x -15 =0D =14² +4*15=256=16²x1=(14-16)/2 = -1x2=(14+16)/2=15