For every 3 seconds, the scuba diver dives 0.5 feet
after 15 seconds = your answer
3 x 5 = 15
0.5 x 5 = your answer
your answer = 2.5
2.5 is your answer
hope this helps
Answer:
Solving the equation
by completing the square method we get 
Option B is correct option.
Step-by-step explanation:
We need to solve the equation
by completing the square method.
For completing the square method: we need to follow: 
We are given:

Solving by completing the square

We need to find ? in our case ? is 3 because 2*3= 6 and our middle term is 6x i,e 2(x)(3)=6x.
So, adding and subtracting (3)^2

So, solving the equation
by completing the square method we get 
Option B is correct option.
Suppose:
C=cost
c=cost per kilo-watt hour
w=number of watts
h=number of hours
thus
C=kwhc
where:
k=constant of proportionality:
k=C/(whc)
but
C=15 when w=6000, h=10/60=1/6 hours, c=7.5 cents per kw/h
thus
k=15/(6000*1/6*7.5)
k=0.002
thus:
C=0.002(whc)
hence:
when
h=70*2=140=140/6=70/3 hours the cost will be:
C=0.002(6000*70/3*7.5)
C=2100 cents
C=$21
Preston have to get some correct and some incorrect answers.
Step-by-step explanation:
1) 7/23 + 11/23 + 9/23
7+11+9/23
27/23
= 1 4/23
2) 2 5/7 + 9 4/7
11 9/7
= 11.12
3) 9/20 + 3/5
9+12/20
21/20
= 1 1/20 or 1.05