5/7 : 4/5 = 25/28
6/35 : 18/49 = 7/15
27/28 : 9/56 = 6
28/45 : 63/40 = 32/81 = 0,39
1786
90
32160
x*3=3969
x=3969*(-3)
x= (-11907)
x:2=1342
x=1342:(-2)
x= (-671)
2684:x=2
x= (-2684):2
x= 1342
3x² - 5x - 2 < 0
D = 25 + 24 = 49
x₁ = (5 - 7)/6 = -1/3
x₂ = (5 + 7)/6 = 2
__+_(-1/3)___-_____(2)_+__
Ответ: (-1/3; 2)