Yes, it is true.
This an example of how you describe an absolute value function algebraically:
Let the function f(x) be f(x) = |2x + 3|
Find the positive values of the argument: 2x + 3 ≥ 0 => x ≥ -3/2
Then,
f(x) = 2x + 3 for x ≥ -3/2; and
f(x) = -2x - 3 for x < -3/2