The numbers -3, -4, and 6 are used once and substitued at random for a, b, and c in the equation ax+b=c. What is the probability that x turns out to be negative.

Question

I'm not sure where to begin with this. Can you help?

Answer 1

First solve for x.

x = (c-b)/a

Then make a table of all possible a,b, c permutations and calculate the corresponding x.

a b c x
_____________

-3.-4. 6..-10/3
-3. 6. -4.. 10/3
-4.-3...6.. -9/4
-4..6..-3.. 9/4
6..-3..-4.. -1/6
6..-4..-3.. 1/6

Half of the possibilties lead to a positive value of x.

Answer 2

ahhhhhh thanks!