Answer:
4 brothers and 3 sisters
Step-by-step explanation:
Let x be the number of brothers and y be the number of sisters in the family.
1. Each brother has x-1 brothers and y sisters. If each brother has as many sisters as brothers, then
![x-1=y.](https://tex.z-dn.net/?f=x-1%3Dy.)
2. Each sister has y-1 sisters and x brothers. If each sister has twice as many brothers as she has sisters, then
![2(y-1)=x.](https://tex.z-dn.net/?f=2%28y-1%29%3Dx.)
3. Solve the system of two equations:
![\left\{\begin{array}{l}x-1=y\\ \\2(y-1)=x\end{array}\right.\Rightarrow 2(y-1)-1=y,\\ \\2y-2-1=y,\\ \\2y-y=2+1,\\ \\y=3.](https://tex.z-dn.net/?f=%5Cleft%5C%7B%5Cbegin%7Barray%7D%7Bl%7Dx-1%3Dy%5C%5C%20%5C%5C2%28y-1%29%3Dx%5Cend%7Barray%7D%5Cright.%5CRightarrow%202%28y-1%29-1%3Dy%2C%5C%5C%20%5C%5C2y-2-1%3Dy%2C%5C%5C%20%5C%5C2y-y%3D2%2B1%2C%5C%5C%20%5C%5Cy%3D3.)
Then
![x=y+1=3+1=4.](https://tex.z-dn.net/?f=x%3Dy%2B1%3D3%2B1%3D4.)
Answer:
A.... -5
Step-by-step explanation:
<u><em>-35 + 30 = -5</em></u>
The easiest way to tell if a number is rational or not is to attempt to express it as a fraction. If you can, then the number is rational. If not, then the number is irrational. All integers are rational numbers, because they can be written as a fraction (for example, the integer 8 = 8/1). But numbers like pi or sqrt(2) cannot be written as a fraction and are not rational.
Answer:
every new hour, the previous amount of bacteria is multiplied by four.
Step-by-step explanation:
Answer:
20.32 cm for each bracelet.
Step-by-step explanation:
121.92 ÷ 2 = 60.96
60.96 ÷ 3 = 20.32