12*(-3/4)-3*5/6=-9-2,5=-11,5
A(t)=cos(t/2)
v(t)=∫cos(t/2)dt+C=2sin(t/2)+C
v(<span>2π/3)=2sin(</span><span>2π/6)+C</span>=√3
2sin(π/3)+C=√3
2*√3/2+C=√3
C=0
v(t)=2sin(t/2)
x(t)=∫2sin(t/2)dt+C=-4cos(t/2)+C
x(2π/3)=-4cos(2π/6)+C=2
-4cos(π/3)+C=2
-4/2+C=2
-2+C=2
C=4
x(t)=-4cos(t/2)+4
ВС=3х+47
DE=10
CD=27+x-(x+26)=1
2х+5у=9 1)2х+5у=9 1,5х-у=2 5у= 9-2х у = (9-2х) /5 2) 1,5х - (9-2х)/5 =2 3) у= (9-4)/5 1,5х-1,8+0,4х=2 у=5/5 1,9х=3,8 х=2 у=1