Solution:
Let x represent a number of calling minutes. According to the problem, we want:

now, putting the similar terms together, we obtain:

this is equivalent to:

now, solving for x, we get:

then, the correct answer for the first question is:
400 minutes is the number of minutes the two plans cost the same
now, for the second question, we can replace the above value (400 minutes) into the following equation:

so that, the correct answer for the second question is:
$55 is the cost when the two plans cost the same
the formula for perimeter is l+l+w+w
So 9+9+6+6= 30 meters of fence
Answer:
-5
Step-by-step explanation:
a positive divided by a negative will always give you a negative
In logarithm, inverse operations are applied.