Question 908555
d=(r+R)*t
2320=(2x+80)*4
2320/4=2x+80
580=2x+80
500=2x
x=250
x+80=250+80
x+80=330
check
2320=(2*250+80)*4
2320=(500+80)*4
2320=580*4
2320=2320
ok