Your answer is correct. A
Answer:
0.75 mg
Step-by-step explanation:
From the question given above the following data were obtained:
Original amount (N₀) = 1.5 mg
Half-life (t₁/₂) = 6 years
Time (t) = 6 years
Amount remaining (N) =.?
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Half-life (t₁/₂) = 6 years
Time (t) = 6 years
Number of half-lives (n) =?
n = t / t₁/₂
n = 6/6
n = 1
Finally, we shall determine the amount of the sample remaining after 6 years (i.e 1 half-life) as follow:
Original amount (N₀) = 1.5 mg
Half-life (t₁/₂) = 6 years
Number of half-lives (n) = 1
Amount remaining (N) =.?
N = 1/2ⁿ × N₀
N = 1/2¹ × 1.5
N = 1/2 × 1.5
N = 0.5 × 1.5
N = 0.75 mg
Thus, 0.75 mg of the sample is remaining.
Answer:
22
Step-by-step explanation:
brainliest?
Answer:
Step-by-step explanation:
(x+3)² -5 =0 , use the formula (a+b) ² = a²+b²+2ab
x²+9 +6x -5 =0 , combine like terms
x²+6x +4 =0, use the quadratic formula x = (-b±√b²-4ac)/2a
x= (-6 ±√6²-4*1*4)/2*1
x= (-6 ± √36-16) /2
x= (-6±√20)/2
x=(-6 +2√5)/2 and x=( -6-2√5) /2, factor 2 in the numerator and simplify
x= -3 +√5 and x= -3 -√5
