Answer:
Explanation:
The $4 additional rental charge is made up at the rate of $1 per game difference in game fees. So charges will be equal when 4 games are played.
The charge for 4 games is 3+4·6 = 27 = 7+4·5.
Each spent $27 for 4 games.
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If you like, you can write equations for the costs.
Rosa's cost for g games is ...
R = 3 +6g
Toby's cost is ...
T = 7 +5g
These costs are the same when ...
R = T
3 +6g = 7 +5g . . . . equate the costs
g = 4 . . . . . . . . . . . . subtract 3+5g*
Costs will be the same for 4 games.
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* You may notice that this is 1·g = 4; the difference in cost per game, multiplied by the number of games, is equal to the difference in rental fees.