4x(x-1)/(x+3) :2(x-1)= 4x(x-1)/(x+3) *1/2(x-1)= 2x/(x+3)
2*2,5/(2,5+3)= 5/5,5= 10/11
v=a*t
-(-5,7)+(-19)-(+3,7)+(+39) = 5,7 -19-3,7+39 = (5,7-3,7) +(39-19) = 2 + 20 = 22