1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jolli1 [7]
3 years ago
13

Use quadratic formula solve .7x^2 - 28x - 7​

Mathematics
1 answer:
beks73 [17]3 years ago
6 0

Answer:

x = 2 + sqrt(5) or x = 2 - sqrt(5)

Step-by-step explanation using the quadratic formula:

Solve for x over the real numbers:

7 (x^2 - 4 x - 1) = 0

Divide both sides by 7:

x^2 - 4 x - 1 = 0

Add 1 to both sides:

x^2 - 4 x = 1

Add 4 to both sides:

x^2 - 4 x + 4 = 5

Write the left hand side as a square:

(x - 2)^2 = 5

Take the square root of both sides:

x - 2 = sqrt(5) or x - 2 = -sqrt(5)

Add 2 to both sides:

x = 2 + sqrt(5) or x - 2 = -sqrt(5)

Add 2 to both sides:

Answer:  x = 2 + sqrt(5) or x = 2 - sqrt(5)

You might be interested in
Which expression represents a number that is four times as large as the sum of 8 and 160?
DedPeter [7]
ANSWER: x = 4 ( 8 + 160 )

STEP BY STEP:

Let's start by getting a variable to represent the number. Let's use x. ⇩

x=

Now we know that there is a sum of 8 and 160. Let's add them to each other ⇩

x= 8 + 160

Now we know that this will be multiplied. Let's put parentheses around the addition to symbolize this.

X= (8 + 160)

Finally multiply this by four, making your equation

x= 4 (8 + 160)

I don't know the options but from looking at the problem I'm assuming the answer is
x = 4 ( 8 + 160 )

8 0
3 years ago
Which contract costs more per month? An 18 month cable contract for $2070 or a 12 month contract at $1776? Which is the better d
Dafna1 [17]

Answer:

Contract A is cheaper because $115 per month is less than $148 per month

Step-by-step explanation:

To find the unit price we divide the total cost given by the total months given for each contract to find out the cost per month.

$2070/18 months = $115 per month

$1776/12 months = $148 per month

Contract A is cheaper because $115 per month is less than $148 per month

7 0
3 years ago
A bus covers a distance of 90km at a uniform speed. Had the speed been 15km/hour it would have taken 30 minutes less for the jou
Brrunno [24]

Answer:

Step-by-step explanation

Let's say d = distance, r = speed and t = time

We know the distance formula is :

distance = speed x time

d = r multiplied by t

d = rt

If the speed is 15km/hr, the time would be 30 minutes shorter.

Since d = rt,

90 = 15t

t = 6,

This means the time taken for the bus to complete the journey at 15km/hr would be 6hrs.

Originally though, the journey takes 30 minutes longer.

So we can say t = 6.5 hrs , and we know d = 90

Now we use the distance formula:

d = rt, since we want to find the original speed, we want to find r.

Speed = distance/time

r = d/t

r = 90/6.5

r = 180/13

Therefore the original speed is 180/13 km/hr

4 0
3 years ago
PLS HELP GIVING BRAINLY FAST
Oksi-84 [34.3K]

Answer:

1) Linear equation

2) Non Linear equation

3) Non Linear equation

4) Linear equation

5) Non Linear equation

i hope this helps!

Step-by-step explanation:

5 0
2 years ago
Find the remainder for the quotient using either substitution or synthetic division.
zaharov [31]

(x - 5) is a factor of the polynomial function f(x) = x³ - x² - 17x -15 as there is no remaider.

<h3>What is a factor of a polynomial?</h3>

We know that if x = a is one of the roots of a given polynomial x - a = 0 is a factor of the given polynomial.

To confirm if x - a = 0 is a factor of a polynomial we replace f(x) with f(a) and if the remainder is zero then it is confirmed that x - a = 0 is a factor.

Given a polynomial function f(x) = x³ - x² - 17x -15.

If (x - 5) is it's factor then f(5) = 0.

∴ f(x) = x³ - x² - 17x -15.

f(5) = 5³ - 5² - 17(5) - 15.

f(5) = 125 - 25 - 85 - 15.

f(5) = 0.

So, the remainder is zero hence (x - 5) is a factor of the polynomial function f(x) = x³ - x² - 17x -15.

learn more about factor of a polynomial here :

brainly.com/question/26354419

#SPJ1

7 0
1 year ago
Other questions:
  • If f(x)=2x to the second power what is f(x) when x=3
    15·2 answers
  • Which two-dimensional shape can be rotated to create this solid object?
    15·1 answer
  • Solve the equation s = a + lw for<br> the variable w.<br> Pls help quick, full explanation!
    8·1 answer
  • Estimate the quotient 19 4/5 + 4 5/8 A.about 3 B.about 4 C.about 6 D.about 5
    13·2 answers
  • HELP QUICK PLEASE!
    9·1 answer
  • Use the equation below to find T, if w= 70, m= 11, and a = 3.
    6·1 answer
  • Please help ASAP, will give BRAINLIEST to the person who tells me what coordinates will JKV be after the 180 degree rotation!!
    8·2 answers
  • Write an expression equivalent to m + m + m + m that is a product of a coefficient and a variable.
    7·2 answers
  • A number d is greater than −5.
    5·1 answer
  • Find each quotient.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!