21 I think I'm not sure tho
Answer:

Step-by-step explanation:
Use distributive property: 
What is -x * x^2? Answer: -x^3
What is 3 * x^2? Answer: +3x^2
What is -x * -4x? Answer: +4x^2
What is 3* -4x? Answer: -12x
What is -x * -6? Answer: +6x
What is 3 * -6? Answer: -18

Combine like terms, and your answer would be....

Hope this helps :)
Have a great day!
The answer is 500 50 times, 10 is 500
Let sandwiches =x and drink =y.
2x+1y=7.50
5x+2y=18
Then solve simultaneously.
Sandwiches, x= 3
Drink, y= 1.5