we know that
If the temperature is no more than 60 degrees
that means
that the temperature is less than or equal to 60
Let
T ------> the temperature

In a number line the solution is the shaded area at left of T=60 (closed circle)
therefore
the answer is the option B
Part 2
In this problem
we have an identity in equation 3
because the left side is equal to the right side
Part 3
we have the equation
7x-3y=-21