Simplify 7x+21/x2+5x+6 divided by x+6/x+2
a. 7/x+6 b. 4x(x+7)/x+10 c. 10/x+7 d. 7/5

The answer is A.  And here's how you get it.  You start by simplifying between the numerator and the denominator in the top fraction. Factor the top and the botttom so you have this: [7(x+3)/(x+3)(x+2)]/[(x+6)/(x+2)].  The (x+3)'s in the top fraction cancel each other out leaving you with [7/(x+2)]/[(x+6)/(x+2)].  When you divide fractions by fractions you change the sign and flip the fraction in the denominator so now you have this: [7/(x+2)]*[(x+2)/(x+6)]. The (x+2)'s cancel each other out then leaving you with 7/(x+6)

x=number of shirts
y=number of DVDs
We can suggest the following system of inequalities.
30x+12y<175

We solve for x:
maxmimun number of y: y<175/12; y<14
30x+12y<175
30x<175-12y
x<(175-12 y)/30           " y" can be:0,1,2,,14

Answer 1= the solution for shirts would be x<(175-12y)/30   ;  
"y " can be:0,1,2,...,14

We solve for y;
 maximum number of DVDs:    x<175/30<5

30x+12y<175
12y<175-30x
y<(175-30x)/12;        "x" can be: 0,1,2,3,4,5.

answer 2: the solutions for DVDs would be: y<(175-30x)/12; 
"x" can be: 0,1,2,3,4,5.