Question

Isabelle is collecting pledges for a walk-a-thon. Her mother has pledged a flat donation of $9, and her grandmother has pledged $1 per mile. If Isabelle walks a certain distance, the two donors will end up owing the same amount. How much will each donor owe?

Answer 1

Key Concepts

• Linear systems
• Word problems

Solving the Question

In this case, we're given the following information:

• Mother = $9
• Grandmother = $1 per mile
• Isabelle walks x miles, mother pledge = grandmother pledge

The mother's donation of $9 will not change no matter how many miles Isabelle has walked, so if both the mother's and grandmother's donations are equal, they must each owe 9$.

Answer

Each donor owes $9.