Step-by-step explanation:
(2x-y+3)(2x-y-3)=
4x²-2xy-6x-2xy+y²+3y+6x-3y-9=
4x²-4xy+y²-9=
(2x-y)²-9
Need a picture! Then I will be happy to help :
It will take 2/3 hour or 40 minutes to fill the tank if both pipes are used.
Let pi be pipe 1 and pi2 be pipe 2
pi = 1 / 1
pi2 = 1 / 2
together = 1/1 + 1/2 ;
3/2 time ; 2/3 hour.
It will take 2/3 hour or 40 minutes to fill the tank if both pipes are used.
Problem-solving is the act of defining a problem; figuring out the motive of the problem; identifying, prioritizing, and deciding on alternatives for a solution; and implementing an answer.
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Answer:
<h2>210</h2>
Step-by-step explanation:
list of prime #s between 12 and 42:
13, 17, 19, 23, 29, 31, 37, 41
now add them up:
13+17+<em>19</em>+<u>23</u>+<em>29+31</em>+<u>37</u>+<em>41</em>
30+60+60+60
90+120
210
