Answer:
a person can work out 50% of the maximum (50% of 194 is 97) and 85% of the maximum (85% of 194 is 164.9). This means that the target heart rate for a 20-year-old is approximately 97–165 bpm. so around 21.
Step-by-step explanation:
Answer:
there may be 16 but I am not sure
Answer: 2x^2-7x-15
Step-by-step explanation:
reorder the terms (x*2+3)*(x-5)
multiply the parentheses
(2x+3)*(x-5)
collect like terms (2x^2-10x+3x-15)
product= 2x^2-7x-15
Since we are given with the identity of the chemical as Carbon-14, we obtain the half-life of the chemical from a reliable source and get a value of 5730 years. The equation that we are going to use for this item is,
A(t)/A(0) = (0.50)^(n/5730)
where A(t) is the current amount, A(0) is the initial amount and n is the number of years. We know from the given that the ratio of A(t) and A(0) is equal to 0.63. Substituting this to the given,
0.63 = 0.50^(n/5730)
n = 3819.48
Thus, the sample is approximately 3819.5 years old.
