Answer:
The main reason it was important to study this group was:
1) If Whitehead had found that many people had drunk water from the Broad Street pump and not caught cholera, that would have been evidence against Snow's hypothesis.
Step-by-step explanation:
But Dr. John Snow was able to convince many councillors who ensured that the pump handle was removed from the Broad Street pump. Within a few days of this removal, the cholera epidemic ended. This step proved that Dr. Snow was right from the beginning. The pump handle was the means that the cholera epidemic was being spread from one person to another within Broad Street area, since many usually fetch water from the pump.
Check the picture below.
make sure your calculator is in Degree mode.
A half-life of the isotope is 15 days and at start its mass is 32 g.
A table:
t: m:
0 32 g
15 16 g
30 8 g
45 4 g
60 2 g
75 1 g
In the first column is used an arithmetic sequence ( a 1 = 0, d = 15 ).
In the second column is used a geometric sequence ( a 1 = 32, r = 1/2 )
0.057x 10 is equal to .57. All you have to do is move the decimal to the right one time because there is one zero in 10.
We need to start from the innermost parenthesis and work our way out.
The first parenthesis is 
. These are not like terms because one involves a variable, while the other is a constant term. Two terms are summable if they involve the same power(s) of the same variable(s).
So, we can take one step outwards, and we arrive to the square brackets. We have
and 2z and -13z are like terms, so we can sum them:
Finally we arrive to the whole expression, which is
Because, again, 5z and 11z were like terms.
