Wilda can do the job in 4 hours ... she does 1/4 (or 0.25) of it each hour.
Karla can do it in 5 hours ... she does 1/5 (or 0.2) of it each hour.
Wilda worked alone for 1 hour ... 0.25 of the job was done before her helper
arrived. So only 0.75 of the job remained to be done together.
Working together, they accomplish (0.25 + 0.2) = 0.45 of the job in 1 hour.
How many times do they need to do 0.45 of the job in order to finish
the 0.75 of it that remains ? That's the number of hours it will take them,
working together.
0.75 / 0.45 = <em>1 and 2/3</em>
After Wilda worked alone for 1 hour and Karla came along to join her, it will
take them another <em>1 hour and 40 minutes</em> to finish the job and go for a swim.
we know that
the volume of a solid oblique pyramid is equal to

where
B is the area of the base
h is the height of the pyramid
in this problem we have that
B is a square

where
<u>
</u>
so


substitute in the formula of volume
![V=\frac{1}{3}*x^{2}*(x+2)\\ \\V=\frac{1}{3}*[x^{3} +2x^{2}]\ cm^{3}](https://tex.z-dn.net/?f=V%3D%5Cfrac%7B1%7D%7B3%7D%2Ax%5E%7B2%7D%2A%28x%2B2%29%5C%5C%20%5C%5CV%3D%5Cfrac%7B1%7D%7B3%7D%2A%5Bx%5E%7B3%7D%20%2B2x%5E%7B2%7D%5D%5C%20cm%5E%7B3%7D)
therefore
<u>the answer is</u>
![V=\frac{1}{3}*[x^{3} +2x^{2}]\ cm^{3}](https://tex.z-dn.net/?f=V%3D%5Cfrac%7B1%7D%7B3%7D%2A%5Bx%5E%7B3%7D%20%2B2x%5E%7B2%7D%5D%5C%20cm%5E%7B3%7D)
Answer: D. (-6,2)
Step-by-step explanation:
y = x + 8
2x + y = -10
v
2x + x +8 = -10
x = -6
y = -6 + 8 ( plug in x (-6) )
y = 2
( x, y) = ( -6, 2)
Answer:
y = -2x+4
Step-by-step explanation:
the equation of the line there is: y = -2x+8
The parallel line to this one should have the same slope as the first one(-2x)
Parallel lines always have the same slopes