Answer:
-5
Step-by-step explanation:
Here,
t2-t1=20-25=-5
t3-t2=15-20=-5
t4-t3=10-15=-5
t5-t4=5-10=-5
 
        
             
        
        
        
7 . 112
8 . 246
for number 7 , you multiply 8 by 16 to get 128 then subtract both windows so you get 112
for number 8 , you find the area of the rectangle which is 10x26 = 260 then add the triangles area which is 130 and you get 390 then subtract the 16 window and 128 door
        
             
        
        
        
Answer:
P = 16x + 8
Step-by-step explanation:
Perimeter of a rectangle 
= 2(L + W)
Given 
L = 5x + 4 and 
W = 3x
Therefore 
Perimeter = 2(5x + 4 + 3x)
Rearrange the expression 
P = 2(5x + 3x + 4)
P = 2(8x + 4)
Now expand the bracket 
P = 2 x 8x + 2 x 4
P = 16x + 8