回答:
#y = -9 rarr x = -17#
#y = -8 rarr x = -16#
#y = -6 rarr x = -14#
#y = -5 rarr x = -13#
#y = -4 rarr x = -12#
#y = -3 rarr x = -11#
説明:
もし #y# 直接変化する #バツ#その後 #バツ# 数値で増減する #n#そうなります #y#.
もし #y = 2# いつ #x = -6# その後:
#y = -9 = 2-11 rarr x = -6-11 = -17#
#y = -8 = 2-10 rarr x = -6-10 = -16#
#y = -6 = 2-8 rarr x = -6-8 = -14#
#y = -5 = 2-7 rarr x = -6-7 = -13#
#y = -4 = 2-6 rarr x = -6-6 = -12#
#y = -3 = 2-5 rarr x = -6-5 = -11#