means that everything below that line should be shaded. To graph the first equation x ≥ 0,shade everything to the right of the y-axis. The resulting picture should look like this:The formula for the area of a triangle is A = b × h. It is easiest to think of the side that is
along the y-axis as the base. That side goes from a y-coordinate of 4 to –4, for a length of 8.
The height of the triangle is the x-coordinate of the point where the two slanted lines meet;
set the two equations equal to find it. Start with x − 4 = – x + 4 and multiply everything
by 15 to get 10x − 60 = – 6x + 60. Then add 6x and 60 to both sides to get 16x = 120, so x =
7.5, and the height is 7.5. The resulting figure should look like this: