Answer:
-0.523
Step-by-step explanation:
log(a/b)=loga-logb
log (0.3) can be written as log (3/10).
=log(3/10)
=log3-log10
=0.477-1 (log3=0.477 and log10=1)
= -0.523
Answer:
Step-by-step explanation:
Let 
Subbing in:

a = 9, b = -2, c = -7
The product of a and c is the aboslute value of -63, so a*c = 63. We need 2 factors of 63 that will add to give us -2. The factors of 63 are {1, 63}, (3, 21}, {7, 9}. It looks like the combination of -9 and +7 will work because -9 + 7 = -2. Plug in accordingly:

Group together in groups of 2:

Now factor out what's common within each set of parenthesis:

We know this combination "works" because the terms inside the parenthesis are identical. We can now factor those out and what's left goes together in another set of parenthesis:

Remember that 
so we sub back in and continue to factor. This was originally a fourth degree polynomial; that means we have 4 solutions.

The first two solutions are found withing the first set of parenthesis and the second two are found in other set of parenthesis. Factoring
gives us that x = 1 and -1. The other set is a bit more tricky. If
then
and

You cannot take the square root of a negative number without allowing for the imaginary component, i, so we do that:
±
which will simplify down to
±
Those are the 4 solutions to the quartic equation.
Answer:
Time spent on professional calls is typically shorter but less consistent than time spent on personal calls.
Step-by-step explanation:
Professional calls are typically shorter (Median = 4 min) than personal calls (Median = 5 min).
However, they are less consistent (IQR = 5 min) than personal calls (IQR = 2 min).
Explanation:
How many surface has a pyramid?
5 Faces
It has 5 Faces. The 4 Side Faces are Triangles. The Base is a Square.