Answer:
<em>3.12 m</em>
Step-by-step explanation:
13 - 9.88 = 3.12
So, 9.66 - 9.53 will then be 0.13, so if we take 9.66 to be the 100%, what is 0.13 off of it in percentage then?
x+6 is x+6. It's an expression. Not sure what you need help with.
For the sake of example, let's multiply the two numbers

and

together. Altogether, we have:

Rearranging the expression, we can group the exponents and coefficients together:

Multiplying each out, we notice that since

and

have the same base (10), multiplying them has the effect of adding their exponents, which leaves us with:

The takeaway here is that multiplying two numbers in scientific notation together has the effect of multiplying its coefficients and <em>adding</em> its exponents.
Answer:
36.36% probability that she gave birth to quadruplets
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcoes.
Desired outcomes:
Giving births to quadruplets.
She has 4 sets of quadruplets.
So 
Total outcomes:
At least 3 children(triplets).
7 sets of triplets and 4 sets of quadruplets.
So 
Probability:

36.36% probability that she gave birth to quadruplets