## Mathhelp346 3 years ago PLEASE HELP: Trevor is a salesperson who earns a weekly salary and a commission that is 7% of his weekly sales. In one week Trevor's sales were \$952.00 and his weekly income was \$466.64. In another week his sales were \$2515.00 and his weekly income was \$576.05. a. Write a linear equation in slope-intercept form for Trevor's weekly income, y, in terms of his weekly sales, x. b. What is Trevor's weekly salary?

1. tcarroll010

Still there?

2. Mathhelp346

yea

3. tcarroll010

ok, we can do this (me AND you).

4. Mathhelp346

ok

5. tcarroll010

This is just a problem in getting a line from 2 points. y = mx + b. Y will be income. b will be his weekly salary. x will be sales. weekly salary will a constant.

6. Mathhelp346

ok will there be two equations?

7. tcarroll010

You are given 2 values for y and 2 values for x. You can then use (y2 - y1)/(x2 - x1) = m. You can get m from the % of sales commission. Only one equation constructed from the 2 points.

8. Mathhelp346

so do i get multiply the weekly sales by .07 first?

9. Mathhelp346

then i do y2-y1/x2-x1

10. tcarroll010

You multiply mx by x to get the commission in \$.

11. Mathhelp346

but i need the coordinates to do y2-y1/x2-x1

12. tcarroll010

You might want to start with figuring out his base salary. That part will be very easy because you only need one point for that since so much info is given in the problem statement. Use y - mx = b. Use either point, and you will get the rsame correct answer. I worked it out both ways and the answer is the same.

13. Mathhelp346

y-mx=b?

14. tcarroll010

You were given the coordinates. If you read my posts and ascribe the corresponding x's and y's, you will have your coordinates. As i said we are BOTH doing the problem. I do not hand out answers. I give strong hints and set up the problem for people.

15. Mathhelp346

so so the coordinates would be (952,466.64) (2515, 576.05)? but do you multiply the weekly sales(952,2515) by .07 first to get his commission?

16. Mathhelp346

would x be the weekly sales or his commission

17. tcarroll010

You're doing well. You have now identified the coordinates and that is very good. You would multiply m by x (commission rate by sales) to get the commission. They already gave you the y (total income for the week), so you just have to subtract mx from y to get b or the base salary. You can use either point, they both give the same answer.

18. tcarroll010

I have already identified x for you. If you still have a question on that, go back and read my posts.

19. Mathhelp346

ok so i find the slope and then substitute it into y=mx+b to get the salary?

20. tcarroll010

I'm going to answer your questions by asking you questions. What is y?

21. Mathhelp346

total income for the week

22. tcarroll010

good. What makes up the total income for the week (in words and variables)?

23. Mathhelp346

b(weekly sales)

24. Mathhelp346

x(sales)

25. Mathhelp346

b is weekly salary

26. tcarroll010

You're close. You're right about x being sales, but you're off on b. b is his salary. Salary + sales commission (sales x commission rate or x multiplied by m) = income = y. With that info, you are 90% done.

27. Mathhelp346

so if i solve 466.64=.07(952)+b i will get the salary?

28. Mathhelp346

but wouldnt i have 2 equations since i can sub in either one? which one do i use?

29. tcarroll010

yes. If you used the other point, you would still get the same salary also. You can use either point.

30. Mathhelp346

so do i write down both equations?

31. tcarroll010

They are just 2 points on the same line. You don't even need the second point to do this problem. It's there for 2 reasons. 1) to give a person practice digging out of a word problem only that which is essential (sufficient and necessary) to do the problem. And 2) so you can confirm your answer (equation and value for salary) with the second point, which again, isn't that important. You would need the second point if you were not given the value for m, sales commission.

32. Mathhelp346

ok

33. tcarroll010

Last time. One equation. I cannot help you any further. Now, 98% of the work is done.

34. Mathhelp346

ok thanks

35. tcarroll010

good luck.

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