SOLUTION: Well I didn't know which kind of problem it was so I'm wondering if you could help me with a couple questions: If flour comes in 2 pound bags and in 5 pound bags, list all the way

Algebra ->  Expressions-with-variables -> SOLUTION: Well I didn't know which kind of problem it was so I'm wondering if you could help me with a couple questions: If flour comes in 2 pound bags and in 5 pound bags, list all the way      Log On


   



Question 167434: Well I didn't know which kind of problem it was so I'm wondering if you could help me with a couple questions:
If flour comes in 2 pound bags and in 5 pound bags, list all the ways to buy exactly 18 pounds of flour. Draw a graph and loacte the solutions on teh graph. What can you say about the solutions that appear on the graph?
NEXT QUESTION:
Ms. O'Brien has written a math exam with two parts. Part I has 9 questions , and part II has 8 questoins. She wants to know how to assign points to each part so that the total will be exactly 100 points. Find a Diophantine equation that represents this situation and solves Ms. O'Brien's problem.
Make a table to represent tests that ahve 9 qeustions in part I, 8 questions in part II and 200 points in all.

LAST QUESTION:
How can you tell that 4x + 6x = 125 has now whole-number solution?
How can you tell that 5x + 10y = 112
How can you tell whether 6s + 9y = 100 has whole-number solutions?

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Graph the line 2x%2B5y+=+18 and then find the points on the graph that intersect the integer grid. You'll the only two points that fall on integers grid is (9,0) and (4,2)
graph%28400%2C400%2C-10%2C10%2C-10%2C10%2C+%2818-2x%29%2F5%29

Use 9x+%2B+8y+=+100
4x + 6y=125 can;t happen since no combination of even numbers can add to an odd result
5x+10y must end in either 5 or 0. No way to get to 112
Last one:
1)Graph and see if there are points on the grid (assumes grid is on integers)
2)Plug and try (100,91,82,73,64,55,46,37,28,19,10,1) Any any of those evenly divisible by 6? I dont think so