Select each equation that is true A7n + (n - 6) = 8 + (8n -14)
B(9a - b) + (a - b) = 10a
C(5x - 9) - (2x + 4) - 3x = 4x - 5
(-3 } - m)
+ (-m + 2 )
= (-2m - ) -
(-0.8n+1.2) + (-2n-4.2) + (1.2n-0.9) = (-5-0.8n) + (1.1 -0.8n)

.632

step-by-step explanation:

6 * 1/10 = 3/5

3*0.01 = 0.03

3/5 + 0.03 = .63

2*0.002 = .002

.63 + 0.002 = .632

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

source: