Answer:
She must buy 90 tiles for the cost to be the same at both stores
Step-by-step explanation:
Let x be the no. of tiles bought for the cost to be the same at both stores
Margo can purchase tile at a store for $0.89 per tile at shop 1
Cost of x tiles =0.89x
She rent a tile saw for $45.
So, total cost at Store 1 = 0.89x+45
At another store she can borrow the tile saw for free if she buys tiles there for $1.39 per tile.
So, cost of 1 tile = 1.39
Cost of x tiles = 1.39x
ATQ
0.89x+45=1.39x
45=1.39x-0.89x
45=0.5x
90=x
Hence She must buy 90 tiles for the cost to be the same at both stores