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:
4x-15=y
Step-by-step explanation:
The higher the rise over the run the more steep your slope will be thus 4x is less steep than 8x because it does not rise as much.
The y intercept shifted downward means anything (-10>b) can be plausible for b.
Polygons are similar? Well there is no picture provided, so I have no idea what you're talking about. But I think you might be asking if in general all polygons are similar, and if that's the case, they are not. Similar means they are similar in at least one aspect, and all polygons are different from each other, only adding one line for each bigger polygon. So I don't know if this helped you, but I tried anyways.
Since the function f(x) is written in the form y = mx + b, where m is the slope and b is the y-intercept, it currently has a y-intercept of b = 6. If this function is shifted downwards (vertically) by 12 units, its new y-intercept will be: