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## Rachel W.'s Resources

If you are only selecting one candy, then you must find the sum of all the candies so 8 + 6 + 4 = 18. Therefore there are 18 ways to select one piece of candy (18 possibilities to choose from).

probability (answer)

Hi Heather,   The probability of all possible outcomes must always sum to 1. I think in your question the pr(H)= 2/3 (since it cannot be greater than 1 it cannot be 23) which would mean the probability of a tail is 1 - pr(H)= 1-(2/3) = 1/3   Hope this helps!

The first three took place around the 1830's, so it is the last one, D. The settlement of Nacogdoches (the first town in Texas, founded around 1779 if I remember correctly).

Are you using excel?  If so, double-click on the line after you graph the data, choose the Options tab in the Format Trendlines dialogue box, and check the Display r-squared value on chart box.  Note the value of R-squared on the graph.    Coefficient of determination...

This week in geometry one of my students is learning about the different "centers" in a triangle (orthocenter, circumcenter, incenter, etc), as well as the midsegments theorem and triangle inequalities.  To help him visualize why all of these things are true, I had him cut out an acute triangle, an obtuse triangle, and a right triangle and use these to illustrate the concepts... read more

Today one of my Spanish students was learning vocabulary related to personal appearance (hair and eye color, height, etc) and had previously learned professions, so to practice all of this vocabulary, we played a couple rounds of 20 questions. We alternated who was thinking of the person and who was guessing so that she could practice both speaking and listening as well as practice her question... read more

First convert 5 3/4 to an improper fraction by multiplying the denominator and integer and adding the numerator to that product: 5 * 4 = 20 + 3 = 23 so our improper fraction is 23/4   Next, make 46 into a fraction by putting it over 1. To divide fractions, you multiply the first...

Hi Sam,   If something is directly proportional, the formula is y = kx where k is some constant that you have to find. If it is indirectly proportional, then the formula is y = k/x where k is again a constant. Here you have three variables so your formula will be: w = ky/v   First...

As I have mentioned in previous blog posts, I work with students of a variety of levels to improve their Spanish speaking ability. Meeting with a student twice a week can make it quite difficult to keep sessions fresh and exciting and to come up with conversational topics that haven't previously been covered. Today one of my more advanced students wanted to practice using the correct imperfect... read more

Pretend you are Christopher Columbus, writing to the King and Queen of Spain to beg them to finance your trip to the Americas. Explain to them what you need, why it is necessary, what you hope to gain. In Spanish this requires the use of the subjunctive! I have often struggled with finding a fun activity to get students to practice writing the subjunctive in context, and came across this idea... read more

A website I like to use with my SAT students is freerice.com. This website has a vocabulary section which asks students to pick a synonym from a list of 4. For every correct answer, the website donates 10 grains of rice to the World Hunger Programme. It's a great way to study vocabulary and do good at the same time! You can create a profile and the website will track your progress with the... read more

I've found that most students have little to no difficulty understanding the difference between parallel and perpendicular lines when only one plane is involved. Either they never touch, or they intersect at a 90 degree angle, or they just plain intersect. This concept is relatively easy to visualize because it is completely 2 dimensional.  Where the difficulty lies, is visualizing... read more

We know that i = √-1 so i2 = -1.  i3 = -i i4 = 1   This pattern repeats infinitely many times. To determine which power i120 corresponds to, divide the exponent by 4 (since the pattern repeats every 4), and whatever the remainder is from this division...

With division of complex numbers, you cannot leave an i in the bottom. To get rid of it you multiply both the numerator and denominator by the conjugate of the denominator.  A conjugate is where you change the sign of the b term. So in a + bi, the conjugate would be a - bi.   So...

2x/x+4=x/x-1 (answer)

The easiest way to solve this is by cross multiplying: 2x(x-1) and (x+4)x   That yields 2x2 - 2x = x2  + 4x   Then you move everything over to the left side of the equation, by subtracting both terms (since they are positive) so that you are left with...

The slope of a line is determined by the change in y divided by the change in x. (Sometime referred to as rise/run).    To find slope for a line between any two points (x1,y1) and (x2,y2), the general formula is:   (y2-y1)/(x2-x1)    In your case...

First you must look for a greatest common factor. In this case, each term has 4x so we begin by factoring that out to get:   4x(x2 + 7x - 60)=0   Since the product is equal to 0, either 4x = 0 or x2 + 7x - 60= 0.    If 4x = 0, then...

Since you know the standard deviation and the mean, you simply add or subtract the standard deviation to/from the mean.   1st standard deviation above = mean + standard deviation = 14.88 + 2.8 = 17.68 2nd standard devation above = mean + 2standard deviation = 14.88 +...

When you are dividing, you can not have an imaginary number in the denominator (bottom of the fraction), just like you cannot have a radical in the denominator. To get rid of it, you multiply both the top and the bottom by 8i so you will get:   {(-1 - 2i)(8i)}/{(8i)(8i)}   On...

I frequently work with students who wish to improve their conversational Spanish skills. I strongly believe learning to actually speak the language is the hardest part for most students, because it is almost impossible to practice unless you have someone with whom to practice. I have certain students who I see on a weekly or bi-weekly basis, and only tutor them in conversational Spanish. For... read more