50% of 36 means a half of 36 which is 18
For this case, the first thing we must do is define variables.
We have then:
x: number of minutes
y: total cost
We write the algebraic expression that models the problem.
We have then:

Simplifying we have:

Then, by the time the cost is equal to $ 300 we have:

From here, we clear the value of x.
Answer:
an algebraic expression for the problem is:

Given that <span>point L is between M and N on MN. Then
MN = ML + LN
31 = h - 15 + 2h - 8 = 3h - 23
3h = 31 + 23 = 54
h = 54/3 = 18
Therefore, LN = 2(18) - 8 = 36 - 8 = 28.
</span>
<span>-4(5x6)
=</span><span>-4(30)
= - 120</span>