Paula has a large ball of yarn that she is going to use to knit a scarf for the winter. Every square inch on the scarf requires a certain number of yards of yarn from the ball.

A linear model of this situation contains the values (18, 240.72) and (30, 97.2), where x represents the number of square inches knitted on the scarf, and y represents the number of yards remaining on the ball of yarn.

How many yards of yarn did Paula start with?

Question

Paula has a large ball of yarn that she is going to use to knit a scarf for the winter. Every square inch on the scarf requires a certain number of yards of yarn from the ball.

A linear model of this situation contains the values (18, 240.72) and (30, 97.2), where x represents the number of square inches knitted on the scarf, and y represents the number of yards remaining on the ball of yarn.

How many yards of yarn did Paula start with?