The purchase price is: 5456-270=5 186 yuan.

2. If there are X volleyball teams, there are 5/3x football teams and 2x-/kloc-0 basketball teams.

The equation x+5/3x+2x- 1=4 1 gives x=9.

So there are 17 volleyball, 9 football and 15 basketball.

3.？ What do you mean by that? What equations are listed? The equation about what?

With inequalities, there are these 3x+y≥ 100.

x+y= 100

Ps: Is this widely known? I don't know ...

4. Method 1: Let the pen be X and the equation is12x+18 (x-2)+6 =120.

The solution is x=5, so the pen 5 yuan notebook 3 yuan

Method 2: Let the notebook be X and the equation is12 (x+2)+18x+6 =120.

The solution is x=3, so the pen 5 yuan notebook 3 yuan

5. Method 1: Let the length be x and y have the equation x+2(x-5)=35.

y+2(y-2)=35

X= 15 y= 13, so the reasonable area of Xiao Zhao is s =13 *1=143 square meters.

Method 2: Let the width be x and y have the equation 2x+x+5=35.

2y+y+2=35

X= 10 y= 1 1, and the lengths are 15 and 13 respectively.

Therefore, the reasonable area of Xiao Zhao is s =13 *11=143m2.

6. Let the cost of A be x, the cost of B be y, and the equation is 8x+3y=2920.

2x+5y= 1240

Multiply both sides of the second formula by 4 at the same time to get 8x+20y=4960.

Subtract the two expressions (now calculated as subtracting from the above expression) to get 17y=2040.

The solution is x=320 y= 120.

So the cost is 320 * 5+120 *1=1720.

This question ... is too simple ... Do it yourself. If you ask a question, you must do it yourself. This is good for you.