Answer: 21m-49n
7(3m-7n)
Step-by-step explanation:
Hello. Sonny solving this equation, multiplying 4.5 by 1016 will give us 4,572 BTU's a year. However, we are looking for the amount looking for the amount that will burn in 9 years. When you multiply 4,572 by 9, you get 41,148. 41,148 BTU's will be burned in 9 years.
Answer:
2
Step-by-step explanation:

<em>Feel free to mark this as brainliest! :D</em>
Using the De Moivre's Theorem, let us work out for the fourth roots of 81(cos 320° + i sin 320° ).
zⁿ = rⁿ (cos nθ + i sin nθ)
z⁴ = 81(cos 320° + i sin 320° )
z = ∜[81(cos 320° + i sin 320° )]
= ∜[3^4 (cos 4*80° + i sin 4*80°)]
= 3(cos 80° + i sin 80°)
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