Question

List the solution set of 30 – 4 (2.x – 1) < 30, given that x is a positive integer.

Answer 1

30 − 4(2x − 1) < 30

30 − 8x + 4 < 30

34 − 8x < 30

−8x < −4

`x> (-4)/-8`

`x>1/2`

Since x is a positive integer, the smallest integer greater than `1/2`​ is 1.

Thus, the solution set for positive integers is:

{1, 2, 3, 4, 5, ...}