3 because the numbers for x are all different
Hello,
The formula for finding the area of a circular region is:

then:

With the two radius it is formed an isosceles triangle, so, we must obtain its area, but first we obtain the height and the base.

Now we can find its area:
![A_{2}=2* \frac{b*h}{2} \\ \\ A_{2}= [r*sen(40)][r*cos(40)]\\ \\A_{2}= r^{2}*sen(40)*cos(40)](https://tex.z-dn.net/?f=A_%7B2%7D%3D2%2A%20%5Cfrac%7Bb%2Ah%7D%7B2%7D%20%20%5C%5C%20%20%5C%5C%20A_%7B2%7D%3D%20%5Br%2Asen%2840%29%5D%5Br%2Acos%2840%29%5D%5C%5C%20%20%5C%5CA_%7B2%7D%3D%20r%5E%7B2%7D%2Asen%2840%29%2Acos%2840%29)
The subtraction of the two areas is 100cm^2, then:
Answer: r= 1.59cm
Answer:
1/2
Step-by-step explanation:
-4 3 15 -14
--- *--- * --- *------
5 7 16 9
Rewriting
-4 3 5*3 -7*2
--- *--- * --- *------
5 7 4*4 3*3
Canceling like terms
-1 1 1*1 -1*2
--- *--- * --- *------
1 1 1*4 1*1
This leaves
2
---
4
1/2
Answer:
1.25 gallons of alcohol
Step-by-step explanation:
Let x represent the amount of alcohol to add to the mix. Then the total amount of alcohol in the mix is ...
0.15×20 + x = 0.20×(20 +x)
3 +x = 4 + 0.2x . . . . simplify
0.8x = 1 . . . . . . . . . . add -3-0.2x
x = 1/0.8 = 1.25 . . . . divide by 0.8
1.25 gallons of alcohol should be added to make 21.25 gallons of 20% alcohol.