Answer:
15x^2 - 12x^3
Step-by-step explanation:
A rectangular block has 3 parts that play into its volume. length, width and height. The question gives us length and width in the form of x and 3x, so height is what's missing.
It gives us a bit more information saying the sum of its edges is 20. We also have to ask how many lengths, widths and heights are there. That may be a bit hard to understand, but is you are looking at a block I could ask how many edges are vertical, just going up and down. These would be the heights. There are 4 total, and this goes the same for length and width, so 4*length + 4*width and 4*height = 20.
Taking that and plugging in x for length and 3x for width (or you could do it the other way around, it doesn't matter, you get:
4*x + 4*3x + 4*height = 20
4x + 12x + 4h = 20
16x + 4h = 20
4h = 20 - 16x
h = 5 - 4x
Now we have h in terms of x, which lets us easily find the volume just knowing x. To find the volume of a rectangular block you just multiply the length, width and height.
x*3x*(5-4x)
3x^2(5-4x)
15x^2 - 12x^3
Question doesn't give a specific value for x at all so you should be done there. Any number you plug in for x should get you the right answer
Answer:
1. 10m
2. 18 ft
Step-by-step explanation:
These are just ratios. They are both essentially doubling
Answer: -2v-20
Step-by-step explanation: -2 times v is -2v
and -10 times -2 is -20.
Answer:
a. x=1.8?
Step-by-step explanation:
im not really sure but i need help also. Im sorry but i just thought to say something.
Set up a proportion:
=
To solve cross multiply:
3000x=300000
divide both sides by 3000:
3000x/3000=300000/3000
x=100
It will take her 100 hours to drive 4000 miles assuming she continues to travel at this rate.
