1) 12*18 + 4 = 216 + 4 = 220
2) 48 : (20-4) = 48 : 16 = 3
3) (14 - 6) * (13 + 6) = 8*19 = 152
4) 6*7 - 63:9 = 42 - 7 = 35
5) (12 - 4) * (24 : 6) = 8 * 4 = 32
0,36-9/75+2/15= 36/100-19/75=108/300-76/300= 32/300=8/75
(1/2-1/3)-(1/4-1/5) =1/6 -1/20=7/60
3 2/9+4 1/6- 1 8/27=29/9+25/6-35/27=174/54+225/54-0/54=
329/54 = 6 5/54
(12 +13) ¤ 121 + (9 +16) ¤29
4-5/9
4/1 - 5/9
общ.знам. 9
(36-5)/9 = 31/9 = 3 4/9
X^2+px-18=0
x1=9
система уравнений
x1+x2=-p
x1*x2=q
9+x2=-p
9*x2=-18
x2=-2
подставляем в первое уравнение
9-2=-p
p=-7
x2=-2, p=-7