Ответ:x= 65272.35/16.64

Решение;

248,3(362,9/(6,4x+2.2))=2.6

(362,9/(6,4x+2.2)=2.6/248,3

(362,9/ (2.6/248,3) =6,4x+2.2

362,9*248.3/2.6 = 6,4x+2.2

362,9*248.3= 2.6( 6,4x+2.2)

362,9*248.3 = 16.64x +5.72

65278.07-5.72 =16.64x

65272.35=16.64x

x= 65272.35/16.64