The rectangle with vertices (-1,y), (7,y) (7,3) and (-1,3) has an area of 72 square units, and y is positive. What is the value of y?
+2863 
These are the two points, (-1,3) and (7,3). We can count the distance, which is 8.
(-1,y), (7,y)
they must be along x = -1 nad x = 7.
Since we know the area is 72 units, and we know one side of the rectange is 8, then we can figure out the other side. 72 / 8 = 9
So we add 9 (because y must be positive) to both known coordinates (-1,3) and (7,3) to find y.
3 + 9 = 12
3 + 9 = 12
y must be 12.
+2863
These are the two points, (-1,3) and (7,3). We can count the distance, which is 8.
(-1,y), (7,y)
they must be along x = -1 nad x = 7.
Since we know the area is 72 units, and we know one side of the rectange is 8, then we can figure out the other side. 72 / 8 = 9
So we add 9 (because y must be positive) to both known coordinates (-1,3) and (7,3) to find y.
3 + 9 = 12
3 + 9 = 12
y must be 12.
