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3 years ago

What are the solutions of -x^2+4x=x-4

Mathematics

1 answer:

Stolb23 [73]3 years ago

8 0

Answer:

x = -1 and x = 4

Step-by-step explanation:

Step 1: Get everything to one side of the equation so it's set equal to zero..

-x² + 4x = x - 4 becomes...

-x² + 3x + 4 = 0 (subtract x and add 4 to both sides)

x² - 3x - 4 = 0 (divide both sides by -1, we want the x² term to be positive)

(x - 4)(x + 1) = 0 (factor)

x - 4 = 0, then x = 4

and

x + 1 = 0, then x = -1

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Hey! I need this pretty fast- just do the first one though! Thank you! :)

Karolina [17]

Step-by-step explanation:

A. part 1: $1.49 for 6 pencils

1 pencil would cost $1.49 / 6 = $0.24833(5s.f.) = $0.25 (nearest cent)

part 2: $4.60 for 20 pencils

1 pencil would cost $4.60 / 20 = $0.23

best value: part 2 (20pencil pack)

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2 years ago

If parallelogram RSTV has diagonals then RSTV must also be a _______. square and a rectangle rhombus and a rectangle rhombus rec

andrew11 [14]

<span>a rectangle rhombus(parallelogram) since even a parallelogram has diagonals</span>

5 0

3 years ago

PLEASE HELP I REALLY NEED IT!!!! WORTH 100 POINTS

-Dominant- [34]

Answer:

Question 1 : The answer is 143.3 miles

Question 2 : The answer is 120 minutes

Step-by-step explanation:

1.Based on the give conditions:

$43 \times 90 \div 27 \\ calculate \frac{43 \times 90}{27} = \frac{430}{3}$ $= 143.3$

2. 90 miles = 75min

143.3 ÷ 90 = 1.6

75 × 1.6 = 120

so the answer is 120 min

3 0

1 year ago

The state of Maine encourages recycling by giving refunds for certain recycled items. When you recycle a glass bottle, you get b

Klio2033 [76]

Given that cost of 1 drinks in a glass bottle = $2.00

Given that cost of 1 drinks in an aluminum can = $0.50

Given that cost of 1 drinks in a plastic bottle = $1.50

Then sum of costs of 1 drink from each will be = 2.00+0.50+1.50

Given that you buy two of each then total cost will be given by 2(2.00+0.50+1.50)

Hence expression that represents the amount of money you will spend is 2(2.00+0.50+1.50).

Using distributive property, we can rewrite it as:

2(2.00+0.50+1.50)=2*2.00+2*0.50+2*1.50

This is final answer of part A.

----------

Given that refund on 1 drinks in a glass bottle = $0.05

Given that refund on 1 drinks in an aluminum can = $0.10

Given that refund on 1 drinks in a plastic bottle = $0.15

Then sum of refunds on 1 drink from each will be = 0.05+0.10+0.15

Given that you plan to recycle all of the items you purchased then total refund will be given by 2(0.05+0.10+0.15)

Hence expression to represent the amount of refund you will receive is 2(0.05+0.10+0.15).

Using distributive property, we can rewrite it as:

2(0.05+0.10+0.15)=2*0.05+2*0.10+2*0.15

This is final answer of part B.

----------

Net cost is given by difference of total cost and total refund

Net cost = 2(2.00+0.50+1.50) - 2(0.05+0.10+0.15)

= 2*2.00+2*0.50+2*1.50 - (2*0.05+2*0.10+2*0.15)

= 4+1+3 - (0.10+0.20+0.30)

= 8 - 0.60

= 7.40

Hence net cost is $7.40

5 0

3 years ago

What’s the answer?and how do you get it

Kay [80]

the solid is made up of 2 regular octagons, 8 sides, joined up by 8 rectangles, one on each side towards the other octagonal face.

from the figure, we can see that the apothem is 5 for the octagons, and since each side is 3 cm long, the perimeter of one octagon is 3*8 = 24.

the standing up sides are simply rectangles of 8x3.

if we can just get the area of all those ten figures, and sum them up, that'd be the area of the solid.

$\bf \textit{area of a regular polygon}\\\\ A=\cfrac{1}{2}ap~~ \begin{cases} a=apothem\\ p=perimeter\\[-0.5em] \hrulefill\\ a=5\\ p=24 \end{cases}\implies A=\cfrac{1}{2}(5)(24)\implies \stackrel{\textit{just for one octagon}}{A=60} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \stackrel{\textit{two octagon's area}}{2(60)}~~+~~\stackrel{\textit{eight rectangle's area}}{8(3\cdot 8)}\implies 120+192\implies 312$

7 0

3 years ago