So legnth is 7 more than 6 times width
l=7+6w
area=10 cm^2
lw=area
subsitute
7+6w for l
(7+6w)(w)=10
7w+6w^2=10
subtract 10 from both sides
6w^2+7w-10=0
factor
multiply 6 and -10
get -60
now find what 2 numbers multiply to get -60 and add to get 7
the answe ris -5 and 12
split up 7w into that
6w^2+7w-10=0
6w^2+12w-5w-10=0
group
(6w^2+12w)+(-5w-10)=0
undistribute factors
(6w)(w+2)+(-5)(w+2)=0
reverse distribute (ab+ac=a(b+c)
(w+2)((6w)+(-5))=0
(w+2)(6w-5)=0
set each to zero
w+2=0
subtract 2
w=-2
false, legnths cannot be negative
6w-5=0
add 5
6w=5
divide both sides by 6
w=5/6
subsitute
l=7+6w
l=7+6(5/6)
l=7+5
l=12
legnth=12 cm
width=5/6 cm
Okay so this is how I got the answer.... I didn’t lol
Answer:
Step-by-step explanation answer is C
Answer:
y=3x-38
Step-by-step explanation:
We know that Tracy spent $38 in less than 3 times than what Daniel spent. Given this information we can put our eqaution together.
Y=3x-38
Hope this helps! :)
The volume is given by:
V = hx² = 500
We can then clear the height in terms of x:
h = 500 / x².
Area of the base: x²
Areal from the top: x²
Area of the vertical walls: 4xh = 4x (500 / x²) or 2000 / x
The formula sought will then be:
C = 0.15 (area of base) + 0.10 (area of top) + 0.025 (area of vertical walls)
C = 0.15x² + 0.10x² + 0.025 (2000 / x)
Rewriting:
C = .25x² + 50 / x
We derive and match zero to find the critical point:
0 = 0.5x - 50 / x ^ 2
Clearing x we have:
50 / x ^ 2 = 0.5x
x ^ 3 = 50 / 0.5
x ^ 3 = 100
x = 4.64
We derive again:
C '' (x) = 0.5 + 100 / x ^ 3
We evaluate x = 4.64:
C "(4.64) = 0.5 + 100 / (4.64) ^ 3
C '' (4.64)> 0 (x = 4.64 is a minimum)
Solving
h = 500 / x²
h = 500 / (4.64) ²
gives
h = 23.22.
Answer:
The dimensions of the box are 4.64 x 4.64 x 23.22.
The total cost would be $ 16.16.