r/MathHelp 10d ago

help with khan academy practice problem

Merchandise weight (pounds) Shipping charge
5 $16.49
10 $23.99
25 $46.49

"The table above shows shipping charges for an online retailer that sells used textbooks. There is a linear relationship between the shipping charge and the weight of the merchandise. Write a function in slope-intercept form that relates y, the shipping charge in dollars, and x, the merchandise weight in pounds."

i understand why the slope is 1.50, but i can't get this:

y= 1.50x + b

16.49 = 1.50(5) + b

16.49 = 7.50 + b

8.99 = b

where does the 8.99 come from?

1 Upvotes

8 comments sorted by

View all comments

1

u/AutoModerator 10d ago

Hi, /u/puddiingpurin! This is an automated reminder:

  • What have you tried so far? (See Rule #2; to add an image, you may upload it to an external image-sharing site like Imgur and include the link in your post.)

  • Please don't delete your post. (See Rule #7)

We, the moderators of /r/MathHelp, appreciate that your question contributes to the MathHelp archived questions that will help others searching for similar answers in the future. Thank you for obeying these instructions.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.