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3 years ago

What error did anna make?

Mathematics

1 answer:

Lapatulllka [165]3 years ago

6 0

Answer:

The last option

Step-by-step explanation:

she did not change the sign of +6 to -6

the constant term should be -15 and not -3

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System by substitution.<br> Tar 7x - 3y=8<br> y=3x

valentina_108 [34]

Answer:

Step-by-step explanation:

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8 0

3 years ago

Combine like terms to simplify the following expression: 12x + 4y – 3x + 2 – 8y2 + 32

sesenic [268]

Answer: The answer is 9x-8y²+4y+34

Step-by-step explanation: Since the equation is 12x+4y-3x+2-8y^2 + 32

1. combine like terms so- combine 12x-3x= 89x

2. look for other like terms- 2+32= 34

3. since 8y^2 and 4y are not the same you can combine them

4. put them all together- 9x-8y^2+4y+3

That's you answer. Hope this helped

6 0

2 years ago

Read 2 more answers

Laura and Chase wants to go to a baseball game. But, the tickets cost $300 each. Laura only had $20 left because she went shoppi

Natalija [7]

Answer:

No they don’t have enough money

Step-by-step explanation:

No:

54+20=74=that’s not enough

211+189=400

Thats enough but they’re are two of them so it would only be enough for one of them

I HOPE THIS IS WHAT YOU’RE LOOKING FOR AND IF NOT THEN I’M SO SO SORRY

5 0

2 years ago

Kelly bought a book of 20 stamps. She has used 80% of them. A. How many stamps has Kelly used? B. How many stamps does she have

jok3333 [9.3K]

80% of 20 is 80/100 x 20 = 16

So, kelly has used 16 stamps, and has 4 left

4 0

3 years ago

Read 2 more answers

A rectangular storage container with an open top is to have a volume of 24 cubic meters. The length of its base is twice the wid

Mariana [72]

Answer:

419.25

Step-by-step explanation:

The calculation of the cost of materials for the cheapest such container is shown below:-

We assume

Width = x

Length = 2x

Height = h

where, length = $2 \times width$

Base area = lb

= $2x^2$

Side area = 2lh + 2bh

= 2(2x)h + 2(x)h

= 4xh + 2xh

Volume = 24 which is lbh = 24

$h = \frac{24}{2x^2} \\\\ h = \frac{12}{x^2}$

Now, cost is

$= 13(2x^2) + 9(4xh + 2xh)\\\\ = 13(2x^2) + 9(4x + 2x)\times \frac{12}{x^2} \\\\ = 26x^2 + \frac{648}{x}$

now we have to minimize C(x)

So, we need to compute the C'(x)

$= 52x - \frac{648}{x^2}$

C"(x) $= 52x - \frac{1,296}{x^3}$

now for the critical points, we will solve the equation C'(x) = 0

$= 52x - \frac{648}{x^2} = 0\\\\ x = \frac{648}{52}^{\frac{1}{3}}$

$C" = ((\frac{648}{52} ^{\frac{1}{3} } = 52 + \frac{1296}{(\frac{648}{52})^\frac{1}{3} )^3}\\\\ = 52 + \frac{1296}{\frac{648}{52} } >0$

So, x is a point of minima that is

= $(\frac{648}{52} )^\frac{1}{3}$

Now, Base material cost is

$= 13(2x^2)\\\\ = 26(\frac{648}{52} )^\frac{2}{3}$

= 139.75

Side material cost is

$= \frac{648}{x} \\\\ = \frac{648}{(\frac{648}{52})^\frac{1}{3} }$

= 279.50

and finally

Total cost is

= 139.75 + 279.50

= 419.25

4 0

3 years ago