Answer:
40.0 grams
Step-by-step explanation:
An exponential decay function is
.... (1)
where, a is initial value, t is time and r is decay rate.
It is given that element with mass 290 grams decays by 13.2% per minute.
Initial value = 290
Decay rate = 13.2% = 0.132
Substitute a=290 and r=0.132 in equation (1).
Substitute t=14 to find the amount of element remaining after 14 minutes.
Round the solution to the nearest tenth.
Therefore, element with mass 40.0 grams is remaining after 14 minutes.
Answer:
x = -7
Step-by-step explanation:
Our function is . Notice that our possible roots are when x + 4 = 0 and when x + 7 = 0. So, our roots are -4 and -7.
However, the power above x + 4 is even, meaning the graph will simply <em>touch</em> the x-axis at x = -4, but not pass through. The power above x + 7, though, is odd, which means the graph will <em>cross</em> the x-axis.
Thus, the answer is x = -7.