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)
Answer:
3/4 meter
Step-by-step explanation:
Need Common denominators to compare size
2/6 3/4 4/9 which is longer than 2/3?
2/6 compared to 2/3. 2/6 = 2/6 and 2/3 = 4/6.
2/6 < 2/3 so 2/6 is too short
3/4 compared to 2/3 3/4 = 9/12 and 2/3 = 8/12
3/4 > 2/3 so 3/4 is longer than 2/3
4/9 compared to 2/3 4/9 = 4/9 and 2/3 = 6/9
4/9 < 2/3 so 4/9 is too short
(2x^2 + 4x + 6) - (-3x - 5x^2 + 4)
The negative sign separating the expressions is just multiplying the rightmost expression by -1.
(2x^2 + 4x + 6) + (3x + 5x^2 - 4)
Now, let's add together terms that share the same variable.
2x^2 + 5x^2 = 7x^2
4x + 3x = 7x
6 + (-4) = 2
Let's combine each of these terms into one expression.
7x^2 + 7x + 2 is the final answer.
