Answer: equations 1,3,4 and 5 stated has solutions.
Step-by-step explanation:
From the question, (x + 5) + 5 = (x + 5) + 5
The equations that represent the situation are:
1. x + 5 = (5 − x) − 5 :which has one solution
2. x + 5 = (x + 5) − 5 : many solutions
3. x + 5 = (x + 5) − 5: no solution
4. x + 5 = (5 − x) − 5 : many solutions
5. (x + 5) + 5 = (x + 5) + 5: many solutions
Equation 2 has no solution. While the other equations have one and more than one solutions.
Mean = 60 / 4 = 15
13 - 15 = -2
17 - 15 = 2
9 - 15 = -6
21 - 15 = 6
Total of squares = 4 + 4 + 36 + 36 = 80
because this is a sample we divide this by n - 1 ( = 3)
Standard deviation = sqrt (80/3) = 5.16 answer
Speed of current ------ y km/h
<span>distance with the current = 4(x+y) </span>
<span>distance against the current = 5(x-y) </span>
<span>we know that 3.5(x+y) = 70 </span>
<span>x+y = 20 </span>
<span>but 4(x+y) = 4(20) = 80 </span>
<span>then 5(x-y) = 80 </span>
<span>x-y = 16 </span>
<span>x+y=20 </span>
<span>x-y=16 </span>
<span>add them </span>
<span>2x = 36 </span>
<span>x = 18 , then y = 2 </span>