Why must you flip the inequality symbol when you divide by a negative number?

Medium sodas cost $1.25 and hot dogs cost $2.50. natalie’s group brought in pizzas but is buying the drinks at concession stand. how many medium sodas can natalie’s group buy with $20? make a table to show answer.

What are the possible rational zeros of [tex]f(x) = x^4+2x^3-3x^2-4x+18[/tex]

In parallelogram abcd the ratio of ab to bcis 5: 3. if the perimeter of abcd is 32 find ab