#color(green)([(2t)/(t+1) ]+[color(white)(.)4(t-1)color(red)(xx1)color(white)(.)]" "=" "[color(white)(.)2color(red)(xx1)color(white)(.)])#
#color(green)([(2t)/(t+1) ]+[color(white)(.)4(t-1)color(red)(xx(t+1)/(t+1))color(white)(.)]" "=" "[color(white)(.)2color(red)(xx(t+1)/(t+1))color(white)(.)])#
#(2t)/(t+1)+ (4(t^2-1))/(t+1)" "=" "(2(t+1))/(t+1)#
Multiply both sides by #(t+1)#
#2t+4t^2-4=2t+2#
Divide both sides by 2
#cancel(color(white)(.)tcolor(white)(.))+2t^2-2=cancel(color(white)(.)tcolor(white)(.))+1#
#2t^2=3#
#t^2=3/2#
#t=+-sqrt(3)/sqrt(2) ~~1.2247...#
#t=+-sqrt(6)/2~~1.2247...#