The formula for finding the area of an equilateral triangle is
square root of 3 * (a^2/2)
a is the side length so in this case is 6
square root of 3 * (18)
the area is about 15.6
Since slope intercept is y=mx+b, you first want to get rid of the 2x by subtracting it from both sides. after, you should end up with 4y=16-2x or 4y=-2x+16, they both are the same, but some teachers might prefer the slope first. after that, you want to get the y alone, so you divide everything by 4. you should end up with the slope intercept form being y=-2/4x+4, simplified to y=-1/2x+4.
The answer to your question is 2 hope this helps!