Answer:
Step-by-step explanation:
Equations
7x + 3y = 4z
<em>Second equation</em>
x + y = z Multiply the entire equation by 4
4[x + y = z] Now distribute the 4 through the equation
4x + 4y = 4z Both equations = 4z. Equate the lefts.
<em>Third equation </em>
7x+3y = 4x + 4y Subtract 3y from both sides
7x + 3y -3y = 4x + 4y -3y
7x = y + 4x Subtract 4x from both sides
7x - 4x = y + 4x - 4x Combine
3x = y
Answer: 3x = y
7, 14, 21, 28, 35, 42, 49, 56, 63
Answer:
46,362.80
Step-by-step explanation:
42,778 × 8.38% = 3,584.7964
42,778 + 3,584.7964 = 46,362.7964
The decay formula is
N(t) = N₀ exp(-kt)
where
N₀ = 45 g, original mass
N(t) = mass after time t, days
k = 0.1109, the decay constant.
At half life, N(t) = (1/2)*N₀. Therefore
1/2 = exp(-0.1109t)
Take natural log of each side.
ln(0.5) = -0.1109t
t = ln(0.5)/(-0.1109) = 6.25 days
Answer: 6.3 days (nearest tenth)
