Step-by-step explanation:
it think it will help you
Answer:
d=0
Step-by-step explanation:
Because multiplication is commutative, we can rearrange the expression however we want. So, let's put the constant expressions together, and the variable expressions together:
(3 x 4) x (d^-4 x d^4)
The first term is easy enough: (3 x 4) = 12
For the second term, when exponent terms have the same "base" (in this case, d), the exponents can be added together. So, the second term yields d^(-4 + 4) = d^0. Any number raised to the zero power equals 1, EXCEPT for the sole number of zero. 0^0 is undefined, but any other number raised to the zero power equals 1.
So, if d equals any number other than zero, the expression becomes
(12) x (1) = 12
The best way to express the answer would be that the expression equals 12 except that it is undefined if d=0
Answer:
the 1st one
next
the 3rd one
Step-by-step explanation: edg 2020
Answer is: Solve for x by simplifying both sides of the equation, then isolating the variable.
x = 20.2
Answer:
ai) 73000 gal/yr
aii) $730 per year
b) 1000 days
Step-by-step explanation:
ai) The water usage per day is ...
(4 showers/day)(10 min/shower)(5 gal/min) = 200 gal/day
Then the usage per year is ...
(200 gal/day)(365 days/yr) = 73,000 gal/yr
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aii) The cost of electricity is the cost of heating half the water usage, so is ...
(0.20 kWh/gal)(1/2)(73,000 gal/yr)($0.10/kWh) = $730/yr
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b) The current daily cost of electricity for heating water is ...
($730/yr)/(365 days/yr) = $2/day
If the cost is cut in half, it will be $1 per day. That means the savings is $1 per day, so it will take 1000 days to recover the $1000 initial cost. (Effectively, the average cost for the first 1000 days is the same as if the water heater had not been replaced.)
