A digit is a number in one of the places, so for example the number 54 has two digits; a tens place digit (5) and a ones place digit (4).
Say the mystery number is a two digit number = xy
* that's not x times y but two side by side digits.
Info given:
<span>the sum of the digits of a two-digit number is 6
x + y = 6 </span>
<span>if the digits are reversed, yx the difference between the new number and the original number is 18.
**To obtain the number from digits you must multiply by the place and add the digits up. (Example: 54 = 10(5) + 1(4))
Original number = 10x + y
Reversed/New number = 10y + x
Difference:
10y + x - (10x + y) = 18
9y - 9x = 18
9(y - x) = 18
y - x = 18/9
y - x = 2
Now we have two equations in two variables
</span>y - x = 2
<span>x + y = 6
Re-write one in terms of one variable for substitution.
y = 2 + x
sub in to the other equation to combine them.
x + (2 + x) = 6
2x + 2 = 6
2x = 6 - 2
2x = 4
x = 2
That's the tens digit for the original number. Plug this value into either of the equations to obtain y, the ones digit.
2 + y = 6
y = 4
number "xy" = 24
</span>
<span>The
content of any course depends on where you take it--- even two courses
with the title "real analysis" at different schools can cover different
material (or the same material, but at different levels of depth).
But yeah, generally speaking, "real analysis" and "advanced calculus"
are synonyms. Schools never offer courses with *both* names, and
whichever one they do offer, it is probably a class that covers the
subject matter of calculus, but in a way that emphasizes the logical
structure of the material (in particular, precise definitions and
proofs) over just doing calculation.
My impression is that "advanced calculus" is an "older" name for this
topic, and that "real analysis" is a somewhat "newer" name for the same
topic. At least, most textbooks currently written in this area seem to
have titles with "real analysis" in them, and titles including the
phrase "advanced calculus" are less common. (There are a number of
popular books with "advanced calculus" in the title, but all of the ones
I've seen or used are reprints/updates of books originally written
decades ago.)
There have been similar shifts in other course names. What is mostly
called "complex analysis" now in course titles and textbooks, used to be
called "function theory" (sometimes "analytic function theory" or
"complex function theory"), or "complex variables". You still see some
courses and textbooks with "variables" in the title, but like "advanced
calculus", it seems to be on the way out, and not on the way in. The
trend seems to be toward "complex analysis." hope it helps
</span>
Your answer is 4320 Milimeters :)
A, D, and E are true
One X on the line plot marks one time something happened. So the two x’s above the 1 means that he practiced piano for one hour (see to the right that says hours next to the numbers, so 1=1 hour) two times.
45 minutes is 3/4 of an hour, and is the mark right between 1/2 and 1. There is one x above this mark, so that means Thaddeus practiced for 45 minutes one time, so B is false
Thadeus practiced piano for 30 minutes two times, so C is false because he didn’t mostly practice for thirty minutes.
D is correct because there are 2 Xs above the 0, which means two times he practiced for zero hours, which means he didn’t practice at all.
E is correct because 15 minutes is 1/4 of an hour, so it is the mark between 0 and 1/2. We see there are three x’s there, so that means he practiced for 15 minutes 3 times.
I hope this helps! Let me know if you want me to explain it differently.
