Answer:
Area of triangle is 9.88 units^2
Step-by-step explanation:
We need to find the area of triangle
Given E(5,1), F(0,4), D(0,8)
We will use formula:

We need to find the lengths of side DE, EF and FD
Length of side DE = a = 
Length of side DE = a = 
Length of side EF = b = 
Length of side EF = b = 
Length of side FD = c = 
Length of side FD = c = 
so, a= 8.60, b= 5.8 and c = 4
s = a+b+c/2
s= 8.6+5.8+4/2
s= 9.2
Area of triangle=
So, area of triangle is 9.88 units^2
Answer:
x = -1, y = 1
Step-by-step explanation:
6 + 4x - 2y = 0 (1)
-3 - 7y = 10x (2)
From (1)
6 + 4x - 2y = 0 (1)
4x - 2y = -6 (3)
From (2)
-3 - 7y = 10x (2)
10x + 7y = -3 (4)
4x - 2y = -6 (3)
10x + 7y = -3 (4)
Using elimination method
Multiply (3) by 10 and (4) by 4 to eliminate x
40x - 20y = -60
40x + 28y = -12
28y - (-20y) = -12 - (-60)
28y + 20y = -12 + 60
48y = 48
y = 48/48
y = 1
Substitute y = 1 into (3)
4x - 2y = -6 (3)
4x - 2(1) = -6
4x - 2 = -6
4x = -6 + 2
4x = -4
x = -4/4
x = -1
x = -1, y = 1
The value of x in the equation is -1
The area of a square is always:
A=s^2 where s=side length, in this case:
A=4^2=16 in^2
The perimeter of a square is always:
P=4s, in this case:
P=4*4=16 in
Answer: C.
Step-by-step explanation: I used m.athway