Answer:
The substance half-life is of 4.98 days.
Step-by-step explanation:
Equation for an amount of a decaying substance:
The equation for the amount of a substance that decay exponentially has the following format:

In which k is the decay rate, as a decimal.
k-value of 0.1392.
This means that:

Find the substance's half life, in days.
This is t for which
. So







The substance half-life is of 4.98 days.
The answer is 34, just plug the numbers in
Answer:
(a)2(89x+84)
(b)
Step-by-step explanation:
The dimensions of the larger rectangular field are:
- Length=5x + 12; Width
= 9x + 14.
The dimensions of the smaller rectangular soccer field are:
(a)Area of the part of the field that is outside the soccer field
=Area of the larger rectangular field - Area of the Soccer Field
=(5x+12)(9x+14)-5x(9x)
=(5x)(9x)+70x+108x+168-5x(9x)
=178x+168
=2(89x+84)
(b)Radius of the Semicircular Fountain =2x
From Part (a),
Area of the larger rectangular field - Area of the Soccer Field=178x+168
Area of the Semicircular Fountain =
Area of the Field that does not include the soccer field or the fountain.
=Area of the larger rectangular field - Area of the Soccer Field-Area of the Semicircular Fountain

Answer:
x=11
Step-by-step explanation:
y= 1/4x
5x-8y=33
5x-8(1/4x)=33
x=11
Answer:
The question is incomplete, the complete question is "Changing Bases to Evaluate Logarithms in Exercise, use the change-of-base formula and a calculator to evaluate the logarithm. See Example 9.
.

Step-by-step explanation:
From the general properties or laws of logarithm, we have the

where both log are now express in the natural logarithm base.
i.e 
hence we can express our
.
the value of ln7 is 1.9459 and ln4 is 1.3863
Hence
.
