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2 years ago

15

Pls help ill give brainlist

2 answers:

Elden [556K]2 years ago

8 0

Answer:

2

Step-by-step explanation:

$24 equals 7 pencils, each x dollars worth, and the $10 left over: 24=7x+10.

Solve for x, 24-10=7x

14=7x

$2=x

The cost of each pencil is $2

DaniilM [7]2 years ago

4 0

Answer:

$2

Step-by-step explanation:

→ Work out how much she spent

24 - 10 = 14

→ Divide it by the amount of pencils

14 ÷ 7 = 2

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The change in the value of an account when given to the nearest dollar 1/16 inch

Feliz [49]

This would be 2 because of the rounding rules of it being 5 and up round up and below 5 round down. I hope I helped!

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2 years ago

A line passes through (-1,5) and (1,3) what is the equation of the line

chubhunter [2.5K]

Answer:

y = -x + 4

Step-by-step explanation:

(-1,5)...x1 = -1 and y1 = 5

(1,3)....x2 = 1 and y2 = 3

slope(m) = (y2 - y1) / (x2 - x1) = (3 - 5) / (1 - (-1) = -2 / (1 + 1) = -2/2 = -1

y = mx + b

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4 0

2 years ago

Which part is which from the circle

gizmo_the_mogwai [7]

<h3>Check out the diagram below for the proper labeling</h3>

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2 years ago

Find three positive numbers whose sum is 140 and whose product is a maximum. (Enter your answers as a comma-separated list.)

Paladinen [302]

Answer:

$\frac{140}{3}, \frac{140}{3}, \frac{140}{3}$

Step-by-step explanation:

Let the numbers be $x, y\ and\ z.$

Such that:

$x + y + z = 140$

Make z the subject

$z = 140 -x - y$

For their product to be maximum, we have:

$f(x,y,z) = xyz$

Substitute $z = 140 -x - y$ in $f(x,y,z) = xyz$

$f(x,y) = xy(140 - x - y)$

Open bracket

$f(x,y) = 140xy - x^2y - xy^2$

Differentiate w.r.t x and y

$f_x=140y - 2xy - y^2$

$f_y=140x - x^2 - 2xy$

Since the products are maximum, then $f_x = f_y = 0$

For $f_x=140y - 2xy - y^2$

$140y - 2xy - y^2 = 0$

Factorize:

$y(140 - 2x - y) = 0$

Split

$y = 0\ or\ 140 - 2x - y = 0$

Make y the subject

$y = 0\ or\ y = 140 - 2x$

For $f_y=140x - x^2 - 2xy$

$140x - x^2 - 2xy = 0$

---------------------------------------------------

Substitute y = 0

$140x - x^2 -2x*0 = 0$

$140x - x^2 = 0$

Factorize

$x(140 - x)= 0$

$x = 0\ or\ 140-x = 0$

$x = 0\ or\ x = 140$

---------------------------------------------------

Substitute $y = 140 - 2x$

$140x - x^2 - 2xy = 0$

$140x - x^2 - 2x(140 - 2x) = 0$

$140x - x^2 - 280x + 4x^2 = 0$

Re-arrange

$4x^2 -x^2 +140x - 280x = 0$

$3x^2 -140x = 0$

Factor x out

$x(3x - 140) = 0$

Divide through by x

$3x - 140 = 0$

$3x = 140$

$x = \frac{140}{3}$

Recall that: $y = 140 - 2x$

$y = 140 - 2 * \frac{140}{3}$

$y = 140 - \frac{280}{3}$

Take LCM

$y = \frac{140*3-280}{3}$

$y = \frac{140}{3}$

Recall that:

$z = 140 -x - y$

$z = 140 - \frac{140}{3} - \frac{140}{3}$

Take LCM

$z = \frac{3 * 140- 140 - 140}{3}$

$z = \frac{140}{3}$

Hence, the numbers are:

$\frac{140}{3}, \frac{140}{3}, \frac{140}{3}$

8 0

2 years ago

Sandeep used 8 litres of fuel to travel 76 miles.

OleMash [197]

Answer:

I got, when calculated, 209 miles. (It may be wrong)

Step-by-step explanation:

First, I calculated how many miles can Sandeep travel with 1L, therefore I divided 76 miles by 8L and got 9.5 miles on 1L.

Then I multiplied 9.2 miles by 22L and got 209 miles.

This may be wrong but if anyone else is able to work it out much appreciated if it's correct.. Your most welcome!

4 0

2 years ago