69-(97-x)=45 (697+х)-345=329 Быстрей )
69-(97-х)=45 69-97-х=45 х=45-69+97 х=73
69-(97-х)=45 69-45=24 97-24=73 х=73 (697+#)-345=329 345+329=674 697-674=23 =-23
697+x = 329+345 697+x =674 x = 674 - 697 x = -23