math -5< 5/2 k?

Answer 1

The previous answer lead to correct conclusion that k > -2, but in this case I belive that the above formula should be proven to be true for all positiva k's, but since we got that k should be greater than -2 that is true for every positive k...

Answer 2

Multiply both sides of the inequality by 2. Then divide both sides by 5.

-5< 5/2 k
-5(2) < 5 k
[-5(2)] / 5 < k
-10 / 5 < k
-2 < k

In this case, we don't reverse the direction of the inequality sign because we didn't divide or multiply by a negative number. Try k = -2 and values greater and smaller than k = -2 to see what results.