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3 years ago

12

What does -6y=18 equal

2 answers:

sveta [45]3 years ago

7 0

Divide both sides by 6
-y=3
times both sides by -1 to have y as a positive
y=-3

Natali [406]3 years ago

6 0

Its -3 or 3 sorry if you get it wrong if its not tight.

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PLEASE HLPP EXTRA POINTS AND BRAINLIEST!!!!!!!!!!!!!

Marat540 [252]

Answer: I think number three is 60 I think it is

Step-by-step explanation:

8 0

3 years ago

A box with a rectangular base and open top must have a volume of 128 f t 3 . The length of the base is twice the width of base.

noname [10]

Answer:

$Width = 4ft$

$Height = 4ft$

$Length = 8ft$

Step-by-step explanation:

Given

$Volume = 128ft^3$

$L = 2W$

$Base\ Cost = \$9/ft^2$

$Sides\ Cost = \$6/ft^2$

Required

The dimension that minimizes the cost

The volume is:

$Volume = LWH$

This gives:

$128 = LWH$

Substitute $L = 2W$

$128 = 2W * WH$

$128 = 2W^2H$

Make H the subject

$H = \frac{128}{2W^2}$

$H = \frac{64}{W^2}$

The surface area is:

Area = Area of Bottom + Area of Sides

So, we have:

$A = LW + 2(WH + LH)$

The cost is:

$Cost = 9 * LW + 6 * 2(WH + LH)$

$Cost = 9 * LW + 12(WH + LH)$

$Cost = 9 * LW + 12H(W + L)$

Substitute: $H = \frac{64}{W^2}$ and $L = 2W$

$Cost =9*2W*W + 12 * \frac{64}{W^2}(W + 2W)$

$Cost =18W^2 + \frac{768}{W^2}*3W$

$Cost =18W^2 + \frac{2304}{W}$

To minimize the cost, we differentiate

$C' =2*18W + -1 * 2304W^{-2}$

Then set to 0

$2*18W + -1 * 2304W^{-2} =0$

$36W - 2304W^{-2} =0$

Rewrite as:

$36W = 2304W^{-2}$

Divide both sides by W

$36 = 2304W^{-3}$

Rewrite as:

$36 = \frac{2304}{W^3}$

Solve for $W^3$

$W^3 = \frac{2304}{36}$

$W^3 = 64$

Take cube roots

$W = 4$

Recall that:

$L = 2W$

$L = 2 * 4$

$L = 8$

$H = \frac{64}{W^2}$

$H = \frac{64}{4^2}$

$H = \frac{64}{16}$

$H = 4$

Hence, the dimension that minimizes the cost is:

$Width = 4ft$

$Height = 4ft$

$Length = 8ft$

8 0

2 years ago

What is the area of these

kumpel [21]

Step-by-step explanation:

The area of a triangle is calculated by multiplying height to the base and that divided by two

G.

13 × 20 ÷ 2 = 130 ft^2

H.

11 × 4 ÷ 2 = 22 ft^2

6 0

2 years ago

1. Harsha makes a scale drawing of a window. She uses the scale 1cm represents 20cm.

guajiro [1.7K]

Part (A)

(1 cm)/(20 cm) = (6 cm)/(x cm)

1/20 = 6/x

1*x = 20*6

x = 120

120 cm = 120/100 = 1.2 m

<h3>Answer: 1.2 m</h3>

=========================================================

Part (B)

2.2 m = 2.2*100 = 220 cm

(1 cm)/(20 cm) = (x cm)/(220 cm)

1/20 = x/220

1*220 = 20*x

20x = 220

x = 220/20

x = 11

<h3>Answer: 11 cm</h3>

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2 years ago

Robbie did a survey of four butterfly parks and wrote the following observations: Butterfly Park SurveyPark Number of White Butt

Snowcat [4.5K]

A = 24 / 86 = 28%
B = 43 / 92 = 47%
C = 12 / 68 = 18 %
D = 32 / 52 = 62%

Answer D

8 0

3 years ago

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