-23
2x+2y/2w+3z
2(-5)+2(8)/2(-2)+3(-3)
-10+16/-4-9
-14-9
-23
Answer: After 7 years the number of birds of species A and B are same. and the number of birds during that year will be 140.
Step-by-step explanation:
Given: Sharon is conducting research on two species of birds at a bird sanctuary.
The number of birds of species A is represented by the equation below,where S represents the number of birds, x years after beginning her research.

The number of birds of species B is represented by the equation below,where S represents the number of birds, x years after beginning her research.

To plot the above function, first find points by which they are passing.
For species A, At x=0 , 
At x=2 , 
Similarly find more points and plot curve on graph.
For species A, At x=0 , 
At x=2 , 
Plot a line with the help of these two points.
Now, from the graph the intersection of curve (for A) and line (for B) is at (7,140) which tells that After 7 years the number of birds of species A and B are same. and the number of birds during that year will be 140.
Answer:
21 windows
Step-by-step explanation:
collen family plans to paint the windows of their house. her father will paint twice as many windows as her mother, and collen and her 2 brothers will paint an equal number of the rest of the windows. Colleen decided to do her own share and her mother's share and paints 7 window, which is one less than her father's share. how many windows are in their house?
Answer: Let the number of window Collen father would paint be a while that of her mother be b. Since her father will paint twice as many window as her mother, therefore the number of windows painted by the father a = 2b
Let the number of windows that would be needed to be painted each by Colleen and her 2 brothers be c because they would paint the equal number of windows.
The total number of windows to be painted = 2b + b + c + c + c = 3b + 3c = 3(b + c).
Collen painted 7 windows as her mother and her own share which is one less than the fathers share. Therefore b + c = 7.
Also the fathers share a = 2b = 7 + 1 = 8 windows. Therefore b = 4 which is the mother share
Therefore the total number of windows = 3(b + c) = 3(7) = 21 windows
3b + 3c = 21
3(4) + 3c = 21
12 + 3c = 21
3c = 21 - 12
3c = 9
c = 3 which is collen and her brothers share