For this case we have the following equation:

To clear w, we must follow the following steps:
1) The value of t multiplied by c pass to divide the other side of the equation:
2) the value of 1000 is passed to multiply to the other side of the equation:
Answer:
The cleared equation for w is:
Answer:
22.5 miles per hour
Step-by-step explanation:
<u>Given system of equations</u>
5(s-w)=900
4(s+w)=900
<u />
<u>Set equations equal to each other</u>
5(s-w)=4(s+w)
5s-5w=4s+4w
s-5w=4w
s=9w
<u>Solve for w using the substitution s=9w</u>
4(s+w)=900
4(9w+w)=900
4(10w)=900
40w=900
w=22.5
Therefore, the speed of the wind is 22.5 miles per hour
I believe it’s the first one. 1.5 + 2 = 3.5
#3 is not a function because there are two answers for one out put
#4 is a function because it is a straight line