1. bobby would be 21 and chris 18.
Answer:
The mass of the radioactive sample after 40 minutes is 12.8 g.
Step-by-step explanation:
The mass of the sample can be found by using the exponential decay equation:

Where:
N(t): is the amount of the sample at time t =?
N₀: is the initial quantity of the sample = 120 g
t = 40 min
λ: is the decay constant = 0.056 min⁻¹
Hence, the mass of the sample after 40 min is:

Therefore, the mass of the radioactive sample after 40 minutes is 12.8 g.
I hope it helps you!
Answer:
x = (4 + 2√34)/10, x = (4 - 2√34)/10
Step-by-step explanation:
5x² - 4x = 6
Subtract: 5x² - 4x - 6 = 0
Quadratic formula: x = (4 ± √(16 - 4*5*(-6)))/10
Multiply: x = (4 ± √(16 + 120))/10
Simplify: x = (4 ± 2√34)/10
Each term has a common divisor of
:

133 = 7*19, so the number in the blanks is
.
Answere: I believe that the answere is C.
Step-by-step explanation:
Well,since the lines A and B are paralel and the line y is not paralel with any of then y and A are not paralel.Plus there is not a line called x in this particular equazion.If you have any questions , please contact me.
Yours sincerely,
Manos