The absolute value of a real number #x# may be interpreted as its distance from #0# on the number line. More formally, for all #x inRR# #|x| = x# if #x >= 0# #|x| = -x# if #x < 0#
As #-25 < 0# and #20 >= 0# that means #|-25| = 25# and #|20| = 20#
thus