Answer: Choice B) The expression (10-2x)(30-2x)x represents the volume of the box
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The original width is 10 inches. The width reduces to 10-2x inches after we cut off the top two corners of the rectangle. We can think of it as taking 10 and subtracting off two copies of x like so: 10-x-x = 10-2x
Similarly, the length goes from 30 inches to 30-2x inches. This time we're taking off the top and bottom corners (focus on either side it doesn't matter).
The height of the box is x inches due to this portion being folded up.
Volume of box = (width)*(length)*(height)
Volume of box = (10-2x)(30-2x)x
Note: the units for the answer are in cubic inches which can be written as "in^3" (inches cubed).
Answer:
-2
Step-by-step explanation:
Answer:
x=2
Step-by-step explanation:
45. These word problems often seem to be two equations in two unknowns, here <em>h</em> for hits and <em>m</em> for misses.
"After 30 tries" translates into

+5 for a hit, -10 for a miss, John lost 90 translates to

We have





Answer: 14
Check: 5(14)-10(16)=-90, good
46. We have to make the odd assumption the grocer sells for his cost, but let's not beat up the question too hard.
Again, two unknowns, <em>b</em> kilograms of Brazil nuts and <em>c</em> kilograms of cashews.
<em>... sold 12 kg of the mixture ...</em>

<em>... cashews $8/kg and Brazil nuts $10/kg and the results is $8.50/kg ...</em>
This one's a bit more involved to translate because we have to recognize the total price is the 8.50 per kg times 12 kg.

The solving is pretty much just like the last one; we eliminate the unknown we're not asked for.




Answer: 9
Check: (9(8)+10(3))/12=102/12 = 8.50 good