Answer:
20 minutes
Step-by-step explanation:
Melissa works as fast as two Bettys, so working together, they get the job done at the rate 3 Bettys could do it. That time is (60 minutes)/3 = 20 minutes.
Working together, Betty and Melissa can mow the lawn in 20 minutes.
_____
You can also think in terms of mowing rates as lawns per minute. The total mowing rate is ...
Betty's rate + Melissa's rate = (1/60 lawns/min) +(1/30 lawns/min)
= (1/60 +2/60) lawns/min = 1/20 lawns/min
The inverse rate is then ...
20/1 min/lawn
Together, they take 20 minutes to mow 1 lawn.
Answer:
Step-by-step explanation:
<u>Given inequality:</u>
<u>Solve it:</u>
The graph includes the number line to the right of 5 and the 5 is included, so this point is represented by a full dot.
Correct choice is A
I bet the ODE is supposed to read

Then if
, we have
and
, and substituting these into the ODE gives

Solving for <em>r</em>, we find

so that
and
are two fundamental solutions to the ODE. Thus the general solution is

Given that
and
, we get

So the particular solution is

Answer:
A. 210
Step-by-step explanation: