Стр.25 √3 помогите плиз

74-7=(60+14)-7=60+(14-7)=60+7=67
52-8=(40+12)-8=40+(12-8)=40+4=44
85-6=(70+15)-6=70+(15-6)=70+9=79
85-9=(70+15)-9=70+(15-9)=70+6=76
52-9=(40+12)-9=40+(12-9)=40+3=43
74-6=(60+14)-6=60+(14-6)=60+8=68
85-7=(70+15)-7=70+(15-7)=70+8=78
85-8=(70+15)-8=70+(15-8)=70+7=77