(2 7/9 z+3 1/3)*3/5 = 1/6 z+6 1/2
(25/9 z+10/3)*3/5 = 1/6 z+6 1/2
25*3/9*5 z + 10*3/3*5= 1/6 z +6 1/2
5/3 z + 2- 1/6 z= 6 1/2
10/6 z -1/6 z= 6 1/2 - 2
9/6 z= 4 1/2
3/2 z= 9/2
z= 9/2 : 3/2
z= 9/2 * 2/3
z= 3
Dlina elektrolini.........x km
x/3+21+x/5=x
5x+315+3x=15x
8x+315=15x
7x=315
x=315:7
x=45
(15+21+9=45)
Otvet: 45km
Y-3=0
Y=0+3
Y= 3.
Х+3=4
Х=4-3
Х=1
1+3=4
Вид первообразной: F(y)=2*x^2+2*x^3+c;