P(7,6), Q(1,6), R(4,2)
We have PQ parallel to the x axis. We'll call that the base,
b = 7 - 1 = 6
The altitude is then the y difference h = 6 - 2 = 4
The area is 
Answer: 12 square units
In general we can use the shoelace formula for the area of any polygon given coordinates. We write the points like this:
(7,6), (1,6), (4,2)
(1,6), (4,2), (7,6)
The area is then half the absolute value of the sum of the cross products:

Answer:
y = 4 and x = 12
Step-by-step explanation:
Step by step explanation in the pic. Atleast the way I did it.
Answer:
-2
Step-by-step explanation:
7x-21-10x+20=5
7x-10x-1=5
-3x=5+1
x=-6/3
x=-2
Answer:
570
Step-by-step explanation:
Answer:
It would be (D 8)
Step-by-step explanation: