Stereo

I think it is two.

Case 1: 12

Case 2: 21

-Stereo 

I am sorry guest but your answer is incorrect, the solution to this question should be:

(a^3+3ab^2 = 679)+(a^3-3ab^2=673)=(2a^3=1352)

a^3=676, a=(676^(1/3))

(a^3+3ab^2=679)-(a^3+3ab^2=673)=(6ab^2=6), (ab^2=1)

(676^(1/3) )b^2=1, b^2=1/(676^(1/3))

b=1/(676^(1/6)) 

which means a-b=(676^(1/3))-1/(676^(1/6))

-Stereo 

Please show the sequence you are referring to. 
-Stereo 

Because at least three squares are red and it is a row of five squares you must have R,_,R,_,R

and the two blanks can be either yellow or blue. If you count it out you will get:

R,Y,R,Y,R

R,B,R,B,R

R,Y,R,B,R

R,B,R,Y,R

and you will get the answer 4 ways.

-Stereo 

Please show the sequence you are referring to. 
-Stereo 

Because the probability of being elected as president is equally likely and the probability for a sophomore to be elected is the same as the probability for a freshman to be elected, the answer should be 1/2 

-Stereo 

You didn't put in how many student takes only Spanish but the answer should be 18 if there are 37 students that only take Spanish.

Because the balls and the boxes are both indistinguishable it is way simpler than it looks and the only way to this question is by listing all the possible cases.

Case 1: 4 balls in one box

Case 2: 3 balls in one box and 1 ball in a other box

Case 3: 2 balls in one box and 2 balls in a other box

Case 4: 2 balls in one box and 1 ball in a other box and 1 ball in a other box

Case 5: 1 ball in one box and 1 ball in a other box and 1 ball in a other box and 1 ball in a other box

Which shows that there are only 5 ways to distribute.

well for starters function f is (x+5)/(x-7) which is division and function h is (x+5)(x-7) which is multiplication. 

You can also prove it by inputing numbers. For example, if I input 10 as x function f will become 5 and function h will become 45 which shows that the two functions are not the same.