Answer: The number of letters that must be engraved for the costs to be the same is 125.
Step-by-step explanation:
Since we have given that

We need to find the number of letters.

Hence, the number of letters that must be engraved for the costs to be the same is 125.
Let the 1st number be x; 2nd number be y; 3rd number be z.
x + y + z = 79
x = number we are looking for.
y = x * 5 ==> 5 times the first
z = x + 16 ==> 16 more than the first
Therefor,
x + (x * 5) + (x+16) = 79
1st step, multiply the 2nd number: x * 5 = 5x
x + 5x + x + 16 = 79
Add all like numbers:
7x + 16 = 79
To get x, transfer 16 to the other side and change its sign from positive to negative.
7x = 79 - 16
7x = 63
To get x, divide both sides by 7
7x/7 = 63/7
x = 9
To check. Substitute x by 9.
x + (x * 5) + (x+16) = 79
9 + (9 * 5) + (9 + 16) = 79
9 + 45 + 25 = 79
79 = 79 equal. value of x is correct.
Answer:
V = 2000r³/3
Step-by-step explanation:
We know that the base is a circular disk, so it creates a circle on the xy plane. It would be in the form x² + y² = r². In other words x² + y² = (5r)². Let's isolate y in this equation now:
x² + y² = (5r)²,
x² + y² = 25r²,
y² = 25r² - x²,
y = √25r² - x² ---- (1)
Now remember that parallel cross sections perpendicular to the base are squares. Therefore Area = length^2. The length will then be = 2√25r² - x² --- (2). Now we can evaluate the integral from -5r to 5r, of [ 2√25r² - x² ]² dx.
![\int _{-5r}^{5r}\:\left[\:2\sqrt{\left(25r^2\:-\:x^2\right)}\:\right]\:^2\:dx\\=\int _{-5r}^{5r}4\left(25r^2-x^2\right)dx\\\\= 4\cdot \int _{-5r}^{5r}25r^2-x^2dx\\\\= 4\left(\int _{-5r}^{5r}25r^2dx-\int _{-5r}^{5r}x^2dx\right)\\\\= 4\left(250r^3-\frac{250r^3}{3}\right)\\\\= 4\cdot \frac{500r^3}{3}\\\\= \frac{2000r^3}{3}](https://tex.z-dn.net/?f=%5Cint%20_%7B-5r%7D%5E%7B5r%7D%5C%3A%5Cleft%5B%5C%3A2%5Csqrt%7B%5Cleft%2825r%5E2%5C%3A-%5C%3Ax%5E2%5Cright%29%7D%5C%3A%5Cright%5D%5C%3A%5E2%5C%3Adx%5C%5C%3D%5Cint%20_%7B-5r%7D%5E%7B5r%7D4%5Cleft%2825r%5E2-x%5E2%5Cright%29dx%5C%5C%5C%5C%3D%204%5Ccdot%20%5Cint%20_%7B-5r%7D%5E%7B5r%7D25r%5E2-x%5E2dx%5C%5C%5C%5C%3D%204%5Cleft%28%5Cint%20_%7B-5r%7D%5E%7B5r%7D25r%5E2dx-%5Cint%20_%7B-5r%7D%5E%7B5r%7Dx%5E2dx%5Cright%29%5C%5C%5C%5C%3D%204%5Cleft%28250r%5E3-%5Cfrac%7B250r%5E3%7D%7B3%7D%5Cright%29%5C%5C%5C%5C%3D%204%5Ccdot%20%5Cfrac%7B500r%5E3%7D%7B3%7D%5C%5C%5C%5C%3D%20%5Cfrac%7B2000r%5E3%7D%7B3%7D)
As you can see, your exact solution would be, V = 2000r³/3. Hope that helps!
Answer:
D. Draw KM so that Mis the midpoint of JL, then prove AJKM * A
LKM using SAS.