it says i need to have at least 20 characters so here you go buddy
Answer:
So we know the formula to calculate the area of the circular sector:
S=(r^2*π*a)/306°=
(5^2*3.14*40°)/360°= (1000*3.14) /360=8.72cm^2 so the right alternative should be the first one ,A.
Step-by-step explanation:
r - radius of the circle
a - corner of the circular sector
S - surface
Since you have y alone on one side of the equation......
Use substitution and plug in 1/2x-4 for y in the other equation.
Distribute
Combine like terms
Add 8 to both sides
Divide by 4
and 
Plug this value in for x
Simplify
Multiply everything by 8 and simplify
Divide.....
Your answers are:
Answer:
correct
Step-by-step explanation:
my brain be smart
Let the youngest sister be n years
Lana will be 2n years, as her youngest sister is half her age
The age of the twins separately will be 2n-2 as they are 2 years younger than Lana
So, the equation looks like this:
n + 2n + 2(2n-2) = 45
Now solve for n:
3n + 4n - 4 = 45
7n - 4 = 45
7n = 49
n = 7
So the youngest sister is 7, Lana is 14 and the twins are 12. 14 + 12 + 12 + 7 =45
