Write a system of equations to describe the situation below, solve using substitution, and fill
in the blanks.
Nina is collecting pledges for a walk-a-thon. Her mother has pledged a flat donation of $12,
and her grandmother has pledged $1 per mile. If Nina walks a certain distance, the two
donors will end up owing the same amount. How much will each donor owe? What is that
distance?
Nina's mother and grandmother will each owe $
if she walks
miles.