3[x+3(4x-5)]=15x-24; x+12x-15=5x-8 (divide both sides by 3); 8x=7 (move all the x's to one side), x=7/8
        
                    
             
        
        
        
Answer:
600
Step-by-step explanation:
since it is a right triangle based pyramid, 2 of them will make a cube. so, it is bwh / 2. 
base = 24
width = 10
height = 5
volume = 1200
volume of pyramid = 600
 
        
             
        
        
        
Add all sides.
5x+2+3x+8+4x-1 
Combine like terms
12x+9
Subtract nine to get it on the other side of the equal sign
12x= -9
Divide by twelve
x=-9/12
Simplify
x=-3/4 
Plug in x. 
        
             
        
        
        
The perimeter of the square is 48
There are 4 equal-length sides to the square, making each side 12 in. in length
to find the area, multiply two sides of the perimeter
12 x 12 = 144
Perimeter: 48
Side: 12
Area: 144
hope this helps
        
             
        
        
        
Answer:
Step-by-step explanation:
X= (-7+radical 13)/6
X=(-7-radical 13)/6