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4 years ago

What number must be added to the expression below to complete the square? x^2 -x

Mathematics

1 answer:

Juliette [100K]4 years ago

8 0

Answer:

Option A

Step-by-step explanation:

Given

$x^2-x$

We know that the formula is:

$a^2-2ab-b^2$

The middle term is:

x which should be equal to 2ab. So,

$x = 2ab\\x = 2*x*b\\x/2x = b\\1/2 = b$

So we know now that we will add (1/2)^2 = 1/4 in the given expression to complete the square as the last term is square in the formula.

The expression will become:

$x^2-x+1/4$

Option A is correct ..

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The perimeter of triangle STU is 28.8 centimeters. Which is the perimeter of triangle JKL?

spayn [35]

Answer:

You forgot to add a picture and/or more context.

Step-by-step explanation:

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4 years ago

Danielle wants to buy a magazine for $11. The sales tax is 5%. How much would the total cost of the magazine be with tax include

dimulka [17.4K]

Answer:

$11.55

Step-by-step explanation:

If we convert the percentage to 1.05 and multiply it by 11, it's 11.55.

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3 years ago

nevsk [136]

#Personal computer:-

Total=480

Percent

$\\ \bull\sf\dashrightarrow \dfrac{480}{1500}\times 100$

$\\ \bull\sf\dashrightarrow 32\%$

#Pacemaker:-

$\\ \bull\sf\dashrightarrow 0.26(1500)$

$\\ \bull\sf\dashrightarrow 390$

#Wireless communication:-

$\\ \bull\sf\dashrightarrow 0.18(1500)$

$\\ \bull\sf\dashrightarrow 270$

#Television:-

Percent

$\\ \bull\sf\dashrightarrow \dfrac{150}{1500}\times 100$

$\\ \bull\sf\dashrightarrow 10\%$

#Others

100-(10+18+26+32)=100-86=14%

$\\ \bull\sf\dashrightarrow 0.14(1500)$

$\\ \bull\sf\dashrightarrow 225$

4 0

3 years ago

Read 2 more answers

I really need help! This is last minute and its 1 am. I'm tired so I'm going to leave it to you guys to solve my problems and pr

Illusion [34]

Answer:

<h2><u>question 1</u></h2>

$n^{2} - 20n -96 = 0$

use product and sum method

product = -96

sum = -20

numbers needed = ( -24 , 4)

n - 24 = 0

n + 4 = 0

hence <u>n = 24 and n = -4 </u>

<u></u>

<h2><u>Question 2 </u></h2>

in the form $ax^{2} +bx +c = 0$

= $x^{2} +12x - 48$

make use of the formula :

$\frac{-b+-\sqrt{b^{2} -4ac} }{2a}$

replace values to make 2 equations :

1. $\frac{-12+\sqrt{12^{2} -4*1*-48} }{2*1}$ = 3.17

2. $\frac{-12-\sqrt{12^{2} -4*1*-48} }{2*1}$ = -15.2

hence <u>x = 3.17 and x = -15.2</u>

<u />

<h2><u>Question 3 </u></h2>

use product and sum method

product = 40

sum = -14

numbers needed = (-10 , -4)

x - 10 = 0

x - 4 = 0

hence<u> x = 10 and x = 4</u>

<u />

<h2><u>Question 4 </u></h2>

in the form $ax^{2} +bx +c = 0$

this becomes $5b^{2} -20b-18-7$

= $5b^{2} -20b-25$

can simplify by 5

= $b^{2} -4b-5 =0\\$

use product and sum method

product = -5

sum = -4

numbers needed (-5 , 1)

b-5 = 0

b + 1 = 0

hence <u>b = 5 and b = -1</u>

5 0

4 years ago

Read 2 more answers

Sam & Avery are making small and large birdhouses for a craft show. Small houses sell for $10 and large houses sell for $15.

Lemur [1.5K]

Answer:

8 small houses; 0 large houses
80 small houses; 0 large houses

Step-by-step explanation:

a) The maximum number of houses Sam can build in 24 hours is 8, so the constraint is in construction, not decoration. For each small house Sam constructs, he makes $10/3 = $3.33 per hour of work. For each large house Sam constructs, he makes $15/5 = $3.00 per hour. The most money is to be made by building only small houses.

Sam should make 8 small houses and 0 large houses in 24 hours.

b) If Sam works 8-hour days, then he can complete at most 80 small houses. The constraint remains in construction, so the answer is the same: build only small houses.

_____

If Sam works more than 16 2/3 hours per day, he can build 100 large houses or more, so the constraint moves to decoration. The decorator makes more money by decorating large houses, so all the effort should go to construction of large houses.

If Sam works between 10 and 16 2/3 hours per day, the best revenue will come from some mix. The problem statement is unclear as to how many hours Sam works in 30 days.

5 0

3 years ago