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
34kurt
3 years ago
11

I need help on the Quadratic Formula.

Mathematics
1 answer:
sasho [114]3 years ago
4 0
1. 3x² + 12x - 15 = 0
    x = <u>-(12) +/- √((12)² - 4(3)(-15))</u>
                             2(3)
    x = <u>-12 +/- √(144 + 180)</u>
                           6
    x = <u>-12 +/- √(324)
</u>                     6<u>
</u>    x = <u>-12 +/- 18 </u>
                  6
    x = -2 <u>+</u> 3
    x = -2 + 3                 x = -2 - 3
    x = 1                         x = -5
--------------------------------------------------------------------------------------------
2. 5x² + 11x + 2 = 0
    x = <u>-(11) +/- √((11)² - 4(5)(2))</u>
                           2(5)
    x = <u>-11 +/- √(121 - 40)</u>
                       10
    x = <u>-11 +/- √(81)
</u>                  10
    x = <u>-11 +/- 9</u>
                10
    x = -1¹/₁₀ <u>+</u> ⁹/₁₀
    x = -1¹/₁₀ + ⁹/₁₀        x = -1¹/₁₀ - ⁹/₁₀
    x = ¹/₅                      x = -2
--------------------------------------------------------------------------------------------
3. 2x² - 11x + 14 = 0
    x = <u>-(-11) +/- √((-11)² - 4(2)(14))</u>
                             2(3)
    x = <u>11 +/- √(121 - 102)</u>
                         6
    x = <u>11 +/- √(9)</u>
                  6
    x = <u>11 +/- 3</u>
                6
    x = 1⁵/₆ <u>+</u> ¹/₂
    x = 1⁵/₆ + ¹/₂          x = 1⁵/₆ - ¹/₂
    x = 2¹/₃                  x = 1¹/₃
--------------------------------------------------------------------------------------------
4. 2x² - x - 15 = 0
    x = <u>-(-1) +/- √((-1)² - 4(2)(-15))</u>
                            2(2)
    x = <u>1 +/- √(1 + 120)</u>
                      4
    x = <u>1 +/- √(121)</u>
                   4
    x = <u>1 +/- 11</u>
                4
    x = ¹/₄ <u>+</u> 2³/₄
    x = ¹/₄ + 2³/₄          x = ¹/₄ - 2³/₄
    x = 3                      x = 2¹/₂
<u />
You might be interested in
Classify the number as rational or irrational.
Ainat [17]

Answer:

A. Rational

B. Irrational

C. Rational

D. Rational


i'm 100% sure! just finished my quiz


<em>hope this helps </em>^.^ !!!!

5 0
4 years ago
What is the final step in the problem solving
Anestetic [448]
<span>Implement and follow up on the solution</span>
5 0
4 years ago
Read 2 more answers
The number of hours you work in a week.​
antiseptic1488 [7]

Answer:56 hours a week is what you have to work 8 hours a day 7 days a week

3 0
3 years ago
Adrian is 3 times as old as Anisah now. 4 years ago,Adrian was 28 years older than Anisah . How old will Anisah be in years' tim
Daniel [21]

Lets have Anisah be x right now.

4 years ago, Adrian was (x-4) + 28 = x+24
Right now, Adrian is 3x.

Knowing those two pieces of information, we can say that x+24 is equal to 3x-4. (This is because Adrian is 3x right now, and for 4 years ago, you subtract 4.)

x+24=3x-4
24=2x-4
28=2x
x=14

Right now Anisah is 14, and in 4 years he will be 14+4 = 18.

7 0
2 years ago
You are collecting email addresses from 74 customers per day, which is about 90% of the daily goal of __________ emails per day.
Tanzania [10]
1. The first step is to realize you need to find a number that will be bigger than 74. 
2. All you have to do for this problem is to divide 74 by 90%. You can put this in the calculator by typing in (74 / .9).
3. The answer you get should be 82.22
4. You can check this by multiplying 82.22 by 90%, and it should bring you back to 74. 
5 0
3 years ago
Other questions:
  • Two angles in a triangle measure 102 and 67 ( should have tiny circles at the top). What is the measure of the third angle?
    11·2 answers
  • The population of New York is 1.975x10^7 people
    15·1 answer
  • Please Help I need ot now!!!!!!​ Ms. Moore is purchasing a house and needs to finance a $150,000 mortgage from the bank with an
    7·1 answer
  • For every 30 minutes of tv airtime,there are 8 minute commercials.If 90 minutes of tv airtime are aired,how many minutes of comm
    13·1 answer
  • You measure a piece of rope and find its length to be 12m . Find the percent error of this measurement
    15·1 answer
  • The 9s in 9,905,482
    8·1 answer
  • An 8-pack of toy cars costs $5.97. What is the unit price, rounded to the nearest cent? ​
    15·2 answers
  • Can someone help please
    7·1 answer
  • Simple question lol .
    5·1 answer
  • A support wire that is attached from the top of an observation tower to 20 meters away on the ground. if the support wire and th
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!