SOLUTION: Jayden and Alexa were asked if 6C2 + 6C3 = 7C3 is true. Their calculations showed it was not true, but they both made mistakes in their calculations. Explain and correct their mist

Question 939185: Jayden and Alexa were asked if 6C2 + 6C3 = 7C3 is true. Their calculations showed it was not true, but they both made mistakes in their calculations. Explain and correct their mistakes. I already corrected jaydens mistakes, but i cant figure out how to fix Alexa's. So please help. Alexa added the fractions by using the LCD (least common denominator).
Step 1 6! 6!
--- + ---
2!4! 3!3!
Step 2 6! 4*6!
---- + -----
4*3!3! 4*3!3!
Step 3 5*6!
------
4*3!3!
Step 4 7! 7*6!
---- = -----
3!4! 4*3!3!
Step 5 5*6! 7*6!
----- not equal -----
4*3!3! 4*3!3!

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
6C2 + 6C3 = 7C3
(6*5)/(1*2) + (6*5*3/1*2*3) = (7*6*5/1*2*3)
-------
Multiply thru by 3! to get:
3*30 + 90 = 210
90 + 90 = 210
false
-----------------
Cheers,
Stan H.
-----------------
RELATED QUESTIONS
What is the number of ways letters in the word KOMBINATOORIKA can be rearranged, such... (answered by Edwin McCravy,jiju)

Our teacher asked us this question today and we were asked to figure it out but no one... (answered by ikleyn)

A survey was taken of 100 people to determine their preferences for two breakfast cereals (answered by ewatrrr)

Prove that 6C2 + 6C3 = 7C3 Step 1 6! 6! --- + --- 2!4! 3!3! (answered by Edwin McCravy)

6. Dewey, Cheetum, and Howe is a law firm that handles divorce cases. A previous study... (answered by stanbon)

Lisa and Kay were asked by their mother to clean their room. Lisa can clean her room in 8 (answered by nerdybill)

It has been reported that many college freshmen indicate they will major in business or a (answered by reviewermath)

Help please - I have tried to use the Binominal Distribution formula to solve this... (answered by Edwin McCravy)

This is an annoying problem, I did solve it, but I got it wrong. It says some students... (answered by solver91311)