a man bought a cow and a calf for 990 dollars, paying 8 times as much for the cows as for the calf. what cost of each

Let x = the cost of the calf.  The cow costs 8 times as much, so it costs 8x.  Together they cost $990:

  x + 8x = $990

   9x=990

   x=990/9

   x=110

so the calf cost=110

and cow cost =880

Virtuoso answer.

i would need to see the dot plot : )

step-by-step explanation: