3x(x+3)^2
3x(x^2 + 6x + 9)
= 3x^3 + 18x^2 + 27x
answer
3x^3 + 18x^2 + 27x
Answer:
- 32.823 kJ
- 190.4 kJ
- 260.00 kJ
- 180.012 kJ
Step-by-step explanation:
The conversion factor for food energy or thermochemical calorimetry* is ...
1 calorie = 4.184 J
1000 calorie = 4.184 kJ
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a. 7845 cal = 7845·4.184 J = 32,823 J = 32.823 kJ
b. 4.55·10^4 cal = 4.55·10^4·4.184 J = 1.904·10^5 J = 190.4 kJ
c. 62.142 kcal = 62.142·4.184 kJ = 260.00 kJ
d. 43,024 cal = 43,024·4.184 J = 180,012 J = 180.012 kJ
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* The thermochemical calorie is defined in terms of the heat capacity of water. An international calorie of 4.1868 J is defined in terms of energy, without respect to the heat capacity of water.
Use the substitution method:
2x - 6y = -12
x - 2y = -8
Then x = 2y - 8
Substitute in the first equation:
2(2y - 8) - 6y = -12
4y - 16 - 6y = -12
-2y = 4
y = -2
Now substitute y in one of the two equations given you prefer:
For example x-2*(-2) = -8
x + 4 = -8
x = -12
The solutions are x = -12 and y = -2
