Answer:
   1350 square inches
Step-by-step explanation:
The area of the end trapezoid is ...
   A = (1/2)(b1 +b2)h = (1/2)(12 +36)(5) = 120 . . . . . square inches
The perimeter of the end trapezoid is ...
   P = 13 +12 +13 + 3×12 = 74 . . . . inches
so the total area of the rectangular surfaces (including the bottom) is ...
   (74 in)(15 in) = 1110 in²
The total area of the ramp is this rectangular area plus the two trapezoidal ends:
   total area = rectangle area + 2×trapezoid area
   = 1110 in² +2×120 in² 
   total area = 1350 square inches
 
        
             
        
        
        
 Working backwards:
17-3=14
14/2=7
7 is the second term in the sequence. Continue backwards.
7-3=4
4/2=2
2 is the first term in the sequence, aka your answer.
        
             
        
        
        
The error would be assuming the altitude is a bisector and divides the sides evenly.
        
             
        
        
        
Answer:
x = 2 or 1/4
Step-by-step explanation:
-13/4 -x= 1/2x -1
Collect like terms
-13/4+1=1/2x+x
Using LCM
(-13+4)/4=(1+2x²)/2x
9/4=(1+2x²)/2x
Cross multiply
9(2x)=4(1+2x²)
18x=4+8x²
Turn into quadratic and solve
8x²-18x+4
Using formulae method
-b±(√b²-4ac)/2a
Where a=8, b= -18 and c=4
(-(-18)±(√(-18)²-4(8)(4))/2(8)
(18±(√324-128))/16
(18±√196)/16
(18±14)/16
(18+14)/16 or (18-14)/16
32/16 or 4/16
2 or 1/4