There are actually 5040 ways of arranging the letter knitting.
The perimeter is simple the sum of the side lengths so:
4x-1+4x+2+3x+4=49 combine like terms on left side
11x+5=49 subtract 5 from both sides
11x=44 divide both sides by 11
x=4
-2.8, -2.6, -2.3
Hope this helped :)
6.4 is the answer to your question
We know that
<span>This problem can be represented through the following equation
</span>
A = A₀(1/2)^t/h
where
A-----------> is the amount of substance left after time t
A₀ ----------> is the original amount---------> 2 g
h-------------> is the half-life-----------> 8 days
for A=0.04 g
t=?
0.04 = 2(1/2)^t/8
0.02 = (1/2)^t/8
Take ln on both sides:
ln(0.02) = ln [(1/2)^t/8]
ln(0.02) = (t/8)(ln 1/2)
t = 8*ln(0.02)/ln(1/2)
t = 45.15 days
the answer is 45.15 days