10) 25x² − 110xc + 121c²

\(25x^2=(5x)^2\), \(121c^2=(11c)^2\), а \(-110xc=-2\cdot5x\cdot11c\).

\(25x^2-110xc+121c^2=(5x-11c)^2\).

Ответ: \((5x-11c)^2\)