Question #a72e1

2 Answers
Feb 17, 2018

See explanation

Explanation:

You have two boxes and each has a mixture of apples and oranges.

After removing 12 apples from one box you are left with a number of apples and 10 oranges. This box is priced at $30

After removing 2 oranges from the other box you are left with a number of oranges and 6 apples. This box is priced at $12.

What is the cost of 1 apple and 1 orange?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

At those prices I am glad I do not shop there!

Feb 17, 2018

Write the given equations as
#y = mx + b#

Explanation:

One way to come up with word problems for these equations is to make them into linear functions   #y = mx + b#

#-12x + 10y = 30#   Solve for #y#

1) Add #12x# to both sides to isolate the #10y# term
#10y = 12x + 30#

2) Divide all the terms on both sides by #10# to isolate #y#
#y = 1.2x + 3#

This equation states that
The "total" (total cost or total whatever, which is #y# )
... is calculated by
1) first multiplying #1.2# times #x# (each item)
2) then adding a flat amount of #3# (which is #b# )

So here is a possible word problem:

The Adventure Restaurant has a rock-climbing activity for children.

The restaurant charges each child $1.20 per hour plus a one-time equipment fee of $3 to climb up a rock face.

Question

How much money did the restaurant take in when a birthday party of #10# children spent an hour climbing the rock face?

#y =  1.2x +   3#
#10y = 12.0x + 30#

#10y = $12# (for #10# one-hour climbs) #+ $30# (for #10# kids' activity fees)

Answer
For #10# children, the restaurant collected #$42#

#color(white)(mmmmmmmm)# __ ___ ____

Given #6x-2y=12#   Solve for #y#

1) Subtract #6x# from both sides to isolate #-2y#
#- 2y = - 6x + 12#

2) Divide all the terms on both sides by #-2# to isolate #y#
#y = 3x - 6#

This result means that the total (which is #y# ) amounts to #3# times the "units" (which is #x# ), with #6# subtracted.

Caroline Randolph owns Carolina Farms, which grows heirloom vegetables for upscale CSA clients.

She expects to harvest #3# lb of heirloom carrots per plot, but she also expects to lose #6# lb overall due to moles.

Question
How many pounds of carrots will she net if she plants 20 plots?

Answer
#y = 3  x    - 6#
#y = 3(20) - 6#
#y =   60    - 6#
#y =        54#

She will net #54# lb of heirloom carrots if she plants #20# plots.

#20# plots @ #3# lb ea . . . . . . . . . . . #60# lb
Minus #6# lb eaten by moles . . . #- 6# lb
......................................................................................
Net . . . . . . . . . . . . . . . . . . . . . . . . #54# lb