Question

the equation y = 15x describes the amount of money Sandra earns, where x is the number of hours she works and y is the amount of money she earns. the table shows the amount of money Susan earns for different numbers of hours worked. (a) how much money does Sandra earn per hour? (b) who earns more per hour?

Answer 1

So based on the table, Susan's equation describing her earnings is:

y=8x (x being the hours, y amount earned)

(a) Sandra earns $8 per hour (the factor in front of x in the equation)

(b) Sandra's equation is y=15x which means for every unit of time she adds $15, so her hourly pay is $15. Therefore Sandra earns ($7) more per hour than Susan.

Answer 2

(a) Sandra earns $15 per hour

(b) Sandra earns more per hour

Explanation:

(a) y=15x tells Sandra's earnings for x hours. To find Sandra's earnings for 1 hour, let x=1.

... y = 15·1 = 15 . . . . Sandra earns $15 in 1 hour.

(b) To find Susan's earnings you can choose any number of hours and divide that into the corrsponding number of dollars. The math is really easy if you choose the last table entry:

... $80/(10 hours) = $8/hour

Sandra's earnings of $15 per hour are more than Susan's earnings of $8 per hour.

_____

Another way to compare the wages is to pick one of the hour numbers from the table and compute Sandra's equivalent earnings. Again, if we choose 10 hours, the math is easy

... y = 15·10 = 150

Sandra earns $150 for 10 hours' work, while Susan only earns $80 for the same time.