2) 8,7b-5.3b=b(8.7-5.3)=3.4*2=6.8
4) 1/3a+1/6a=2+1/6a=3/6a;
3/6*12=3/72=1/24
X^2 + x - 42 =0
D= 1+ 168 = 169 = 13^2
x1 = (-1 -13)\2= -14 \2 = -7
x2 = (-1 +13)\2 =12\2= 6
1). 110-24=86
Ответ:он задумал числа 110 и 86
(73142+45826-118967)*(422100:7)=60300
1.) 73142+45826=118968
2.) 118968-118967=1
3.) 422100:7=60300
4.) 1*60300=60300