<span>8-4,2:(2 5/14-1 4/21)=4 целых 15,8/21</span>
<span>1)25/14-14/21=75/42-28/42=47/42</span>
<span>2)-4,2*42/47=-176,4/47</span>
<span>3)8*47-176,4/47=376/42-176,4/42=199,6/42=99,8/21=4 целых 15,8/21</span>
- 7 < 4x - 1 < 3 /+1
- 7 + 1 <4x - 1 + 1 <3 + 1
- 6 < 4x < 4 /:4
- 6/4 < x < 1
x ∈ ( - 1,5; 1)
Y(x) =3x^3-2x^2-5x
y'(x)=9x^2-4x-5
y''(x)=18x-4, y''(x)=0
18x-4=0
x=4/18
x=2/9