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
If f(x)=2x-1 and g(x)=x^2-4, what is g(f(x))
lesantik [10]

Answer:

4x^2 - 4x - 3

Step-by-step explanation:

f(x) = 2x - 1

g(x) = x^2 - 4

g(f(x)) = ?

[substitute the x of g(x) with f(x)]

g(x) = x^2 - 4

g(f(x)) = (2x - 1)^2 - 4

[solve]

[binomial * binomial = quadratic equation]

[use FOIL method (first, outer, inner, last)]

g(f(x)) = (2x - 1)(2x - 1) - 4

g(f(x)) = (2x*2x) + (-2x) + (-2x) + (1) - 4

[combine like terms]

g(f(x)) = 4x^2 - 2x - 2x + 1 - 4

g(f(x)) = 4x^2 - 4x - 3

8 0
2 years ago
How many 1/10s in 2 3/5
Umnica [9.8K]

It'd be clearer if you'd write:  "How many tenths are there in 2 3/5?"

2 3/5        13/5

---------- = ---------- = 26

(1`/10)        1/10

There are 26 tenths in 2 3/5.

5 0
3 years ago
Using the given zero, find one other zero of f(x). Explain the process you used to find your solution.
umka21 [38]
Complex zeroes always occurs as conjugates.
For z = a + b i conjugate is: a - b i
Another zero is : 2 + 3 i.
Verification:
2 + 3 i + 3 - 3 i = - b/a
- b = 4,  a = 1
( 2 + 3 i ) ( 2 - 3 i ) = c / a
4 - 9 i² = c / a
4 + 9 = c / a
c = 13
( x^4 - 4 x³ + 14 x² - 4 x + 13 ) : ( x² - 4 x + 13 ) = x² + 1
x² + 1 = 0
x² = -1,  x = i,  x = -i
The zeroes are: - i , i , 2 + 3 i, 2 - 3 i.
Answer: 
One another zero of f ( x ) is 2 + 3 i.
7 0
3 years ago
Help I’m very confused and was wondering if anyone is willing to help.
beks73 [17]

Answer:

57°

Step-by-step explanation:

LHS angle=RHS angle=57° (vert. opp angles)

5 0
3 years ago
Marcus is 5 7/24 feet tall Ben is 5 5/16 feet tall which of the two boys is taller? Justify your answer
FromTheMoon [43]
To figure out who is taller, we can take each mixed number and find a common denominator.

5/16 (x3) 15/48
7/24 (x2) 14/48

This tells us that Ben is taller because Marcus is shorter than him by 1/48.
5 0
3 years ago
Read 2 more answers
Other questions:
  • Your annual salary is $28,460 your State personal deductions total $88 for a weekly pay period. The state tax rate is 3.6% of ta
    8·1 answer
  • Which one is correct?
    9·1 answer
  • A publishing industry report predicts that magazine subscriptions will drop by 7% each year. If this prediction is correct, then
    7·1 answer
  • Graph quadratic functions f(x)=-2x-20x-50
    9·1 answer
  • What’s the difference between evaluating an expression for a given value of a variable and solving an equation?
    13·1 answer
  • Using the X Method to Factor a Trinomial
    5·1 answer
  • A spinner is divided into 10 congruent sections. Each section is labeled with a number as shown. The spinner will be spun one ti
    12·1 answer
  • Parallelogram PQRS has diagonals that are perpendicular. Based on that, which statement is most correct?
    7·2 answers
  • Determine if each function is linear or nonlinear
    8·1 answer
  • Solve by completing the square​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!