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Mumz [18]
3 years ago
6

Determine the exact value of k so that the quadratic function f(x) = x2 - kx + 5 has only one zero.

Mathematics
2 answers:
galben [10]3 years ago
6 0
I like this question. When we factorise this question the brackets have to be identical.
5 has to be square rooted to become √5. From, FOIL we know that the last digit is times by the other last digit to find the 5, as our brackets are identical this number is the same. The square root of 5.
This number is doubled in identical brackets to find the middle number. so it is 2√5. As there is a minus number there the brackets are: (x-√5)(x-√5). Multiplying this out gives us: x²-2√5 x+5. k=2√5 (or -2√5, depending on if the minus is counted or not)
JulsSmile [24]3 years ago
3 0
f(x)=ax^2+bx+c\\\\\Delta=b^2-4ac\\\\if\ \Delta < 0-no\ zeros\\if\ \Delta=0-one\ zero\\if\ \Delta > 0-two\ zeros


f(x)=x^2-kx+5=0\\\\a=1;\ b=-k;\ c=5\\\\\Delta=(-k)^2-4\cdot1\cdot5=k^2-20\\\\one\ zero\ if\ \Delta=0\\\\therefore\\k^2-20=0\ \ \ \ |add\ 20\ to\ both\ sides\\\\k^2=20\\\\k=\pm\sqrt{20}\\\\k=\pm\sqrt{4\cdot5}\\\\\boxed{k=-2\sqrt5\ or\ k=2\sqrt5}
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Juan was given a gift card for a coffee shop. Each morning, Juan uses the card to buy one cup of coffee. Each cup of coffee cost
Black_prince [1.1K]

Answer:

A=30-2x

Step-by-step explanation:

Cost of one cup of coffee=$2

The original amount of money on the gift card= $30

Juan's expenses in buying coffee, after x morning are \$2\times x.

The amount of money left, A, on the card = (Original amount) - (Total expenses)

A=30-2x

Hence, the equation for, A, the amount of money remaining on the card is

A=30-2x.

7 0
3 years ago
PLZ HELP I WILL MARK BRAINIEST (26+4) divided by 6 = w
creativ13 [48]

Answer:

w = 5

Step-by-step explanation:

(26+4)=30, and 30/6=5, therefore, w = 5.

5 0
2 years ago
Read 2 more answers
1. Subtract (7 – 19i) from (–6 + 12i). A. –13 – 31i B. –13 + 31i C. 13 – 31i D. 13 + 31i
pav-90 [236]

Answer:

Step-by-step explanation:

(-6+12i)-(7-19i)=

-6+12i-7+19i=

-13+31i

(b)

6 0
3 years ago
Read 2 more answers
Another Asap question plzzzz!!!!!!!!!!
Hunter-Best [27]

Answer:

(0,-4)

(2,-1)

The first point because it is the y-intercept

second point because it is found our by 3/2 as the slope. slope is rise/run. so you rise three and move to the side 2. as is the point (2,-1)

Hope this helps

3 0
3 years ago
Paul,Linda,and Aaron make homemade cards. Paul can make 1 card for every 3 cards Linda makes. Linda can make 3 cards for every 2
dimaraw [331]

Answer:

Linda makes 72 more cards than Paul

during the week

Step-by-step explanation:

Here, we want to know how many cards Linda makes than Paul during the week.

We proceed as follows;

From the question;

If Paul makes 1 card, then Linda has made three

Now let’s get their relationship with Aaron;

If Aaron makes 2 cards , Linda has made three

Now since Aaron made 72 cards, Let’s say Linda has made x cards

Let’s get the value of x now

To get the value of x, we simply cross multiply;

2 - 3

72 - x

2 * x = 3 * 72

x = (3 * 72)/2 = 108 cards

Now recall , for every 3 cards of Linda, Paul made only 1;

So the number of cards Paul will make if Linda makes 108 will be 108/3 = 36

So the number of more cards that Linda makes than Paul during the week will be ; 108 -36 = 72 cards

3 0
3 years ago
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