How can I learn to understand it more

The cost c, in dollars, for bananas depends on the weight w,in pounds, of the bananas. this situation is represented by the function rule c=0.5w (graph each function rule.tell whether the graph is continuous or discrete)

1.two more than the quotient of a number and 6 is equal to 7 use the c for the unknown number translate the sentence into an equation

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?