Which is the simplified version of: 7x + 12 + 3x = -6 (x - 7) + 9x

A. 5x = -30

B. 7x = -54

C. 7x = 30

D. 7x = -19

PLEASE DON’T GUESS :(
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Ineed with number 6 , explain how to get 1978

Which of the following would be a good name for the function that takes the weight of a box and returns the energy needed to lift it?

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days