\left[x \right] = \left[ 5\right][x]=[5]2(x+1)/−2 = 8−2 _________
_________ Simplifying
\left[x \right] = \left[ 2\right][x]=[2] = x + 1 + -4
x = -5
First you want to find the surface area of one box
SA=2(l*w)+2(h*l)+2(h*w)
SA=2(12*12)+2(15*12)+2(15*12)
SA=2(144)+2(180)+2(180)
SA=288+360+360
SA=1008 cm² is for one box
Multiply by 4 to get for 4 boxes
4*1008=4032 cm²
1. Given (12+3)x, we can sum the numbers in the parenthesis to get 15x
2. Given 12x+3x, we can factor x to get (12+3)x and get the same as 1.
3. Given (12+3x)x, we have to distribute the x and we have 
4. This expression is already simplified.
Answer:
8/5 or 1.6
Step-by-step explanation:
Rise over run.
Box 1 : 2
Box 2: 3
Box 3: 6