Probably the last one
Use the equation for the area of a triangle 1/2(bxh)
Then multiply that number by 2 to get the area of the complete shape.
So hmmm if you notice y = x² - b is really just the parent function x² with a downward shift of "b". And y = - x² + b is really just x² upside-down shifted upwards by "b". so, both parabolas, look like the picture below, and their vertices is at the origin and then they get shifted, one upwards and the other downwards.
So the rhombus lies in their vertices and intersection points.
now, the area of the rhombus is 54, we're taking the green triangle in the picture, which is half of the rhombus, so its area is 27 then, it has a base of "2b", and an altitude of whatever the value of "x" at the intersection happens to be.
so hmmm let's check what's "x" anyway.
Answer:
y = -x + 15
Step-by-step explanation:
if an item is priced at $9 per item then 6 items are sold.
Thus, the input is 9 while the output is 6.
Thus, we can say; x, y = (9, 6)
4 items are sold for $11 per item. Thus, the coordinate is; (11, 4)
Now,slope is;
m = (y2 - y1)/(x2 - x1)
m = (4 - 6)/(11 - 9)
m = -2/2
m = -1
We know that slope intercept form is;
y = mx + c
Let's try the first point.
Thus;
6 = -1(9) + c
6 + 9 = c
c = 15
Thus, equation of line is;
y = -x + 15