Answer:

Step-by-step explanation:
From C-A, it goes from y=1 to y=5, so that 4 units
From A-B, it goes from x = -1 to x = 4, that is 5 units
Now, to find distance from B to C, we need to use the distance formula:

Where the variables are the respective points of B and C,
B (4,5) & C(-1,1)
So x_1 =4, y_1=5, x_2=-1, y_2=1
Plugging into the formula we get:

Summing it all (perimeter is sum of 3 sides):
Distance = 
3rd answer choice is right.
Substitute in y= equation into 2nd equation to start.
(2,5)
Answer:
4x + 7
Step-by-step explanation:
7x+4-3x+3
First put the like terms together
7x+4-3x+3 = (7x - 3x) + (4 + 3)
= 4x + 7
Answer:
x = 11
Step-by-step explanation:
Given :
AB = x + 5
BC = 2(x - 3)
AB = BC
AB = BC
x + 5 = 2(x - 3)
x + 5 = 2x - 6
5 + 6 = 2x - x
11 = x
x = 11
happy to help :)