SA=2H(L+W)+LW for open box
20=2H(4+W)+4(W)
distribute
20=8H+2WH+4W
divide both sides by 2
10=4H+WH+2W
solve for 1 variable, pick W
10-4H=WH+2W
10-4H=W(H+2)
(10-4H)/(H+2)=W
V=LWH
subsitute 4 for V, subsitute H for H and (10-4H)/(H+2) for W
V=(4)(H)(10-4H)/(H+2)
V=(40H-16H²)/(H+2)
find max value
take deritivitive of this thing
V'=-16(H²+4H-5)/((H+2)²)
using sign chart
sign changes from positive to negative at H=1
so at H=1
find W
W=(10-4H)/(H+2)
W=2
the dimeionts are
length=4ft
width=2ft
height=1ft
(the volume is 8 cubic feet)
You are correct. The answer is D 5:3
Answer:
12x-6
Step-by-step explanation:
perimeter= 2l+2w
=2(x+4)+2(5x-7)
=2x+8+10x-14
=12x-6
Let the second no. be x
-3x = 21 → x = 21/-3 → x = -7
Answer:

Step-by-step explanation:
First of all, the number before the decimal would be the whole number of the fraction.
So, 
Then, you would put 0.83 over a fraction.
So because you cannot simplify it anymore, it would be 