ANSWER:

STEP-BY-STEP EXPLANATION:
We have that the equation in its slope-intercept form is the following:

The slope can be calculated as follows:

We use the points (4,7) and (1,1) to calculate the slope:

Now, we calculate the value of b, using the point (1,1) and the slope, like this:

Therefore, the equation would be:
Answer:
24 Years Old
Step-by-step explanation:
Less than 31 is 30 and 30-6=24
Combinatorial Enumeration. That whole class was a rollercoaster ride of mind-blowing generating functions to prove crazy things. The exam had ridiculous questions like 'count the number of cactus trees with n vertices such that etc etc etc' and you'd do three pages of terrible terrible sums and algebra. Then your final answer would be something beautiful like n/2 and you'd breath a sigh of relief and thank the math gods.