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
Anon25 [30]
2 years ago
9

Please help, and thank you!

Mathematics
1 answer:
lawyer [7]2 years ago
8 0

Answer:

3. C

4. D

Step-by-step explanation:

3.

x^2+25=0\\x^2=-25\\x=\pm\sqrt{-25}

Once \sqrt{-1}=i

x=\pm5i

4.

A quadratic equation has no real roots when the discriminant (\Delta) is negative. \Delta.

Let's try all the equations:

(A)

2x^2-7x-9=0\\\\\Delta=\sqrt{\left(-7\right)^2-4\cdot \:2\left(-9\right)}\\\Delta=\sqrt{\left(-7\right)^2+4\cdot \:2\cdot \:9}\\\Delta=\sqrt{121} \\\Delta=11

(B)

2x^2=7x\\2x^2-7x=0\\x(2x-7)=0\\x=0\\\text{or}\\2x-7=0\\2x=7\\\\

$x=\frac{7}{2} $

(C)

2x^2+7x-9=0\\\Delta = \sqrt{7^2-4\cdot \:2\left(-9\right)}\\\Delta = \sqrt{7^2+4\cdot \:2\cdot \:9}\\\Delta = \sqrt{121} \\\Delta= 11

(D)

2x^2-7x+9=0\\\Delta = \sqrt{\left(-7\right)^2-4\cdot \:2\cdot \:9}\\\\\Delta=\sqrt{-23} \\\Delta=\sqrt{23i}

You might be interested in
The costs of different weights of onions sold at a grocery store are shown in the table below. What are the independent and depe
Furkat [3]

Answer:

Independant = onions wight. Dependent = cost.

Step-by-step explanation: The Cost depends on how much the onions weight.

3 0
2 years ago
Which explanation uses the number line to show 5 + (-5) =0
Ray Of Light [21]

Answer:

+5 is right and - 5 is left

Step-by-step explanation:

I. If 5 + (-5) = 0

  then 5 - 5 = 0

  If 5 is on the right side

   then -5 is on the left side

3 0
2 years ago
HELP ASAP I WILL GIV YOU BRAINLIST! Jim ran 200 meters in 30.4 seconds. Mac ran 100 meters in 30.4 seconds. Who ran faster?
statuscvo [17]

Jim ran faster than Mac.

3 0
3 years ago
Can you help me with this question please
Aleksandr-060686 [28]

Answer:

The actual length of the lap = 250 meters

Step-by-step explanation:

∵ The scale factor of the map is 1:1000

∵ The length of the lap on the map is 25 cm

∴ \frac{1}{1000}=\frac{25}{x}

Where x is the actual length of a lap

∴ x = (25 × 1000) ÷ 1 = 25000 cm

∵ 1 meter = 100 centimeter

∴ The actual length of the lap = 25000 ÷ 100 = 250 meters

7 0
3 years ago
Read 2 more answers
I need the answer to 1+1 please
ycow [4]

Answer:

2

Step-by-step explanation:

8 0
3 years ago
Read 2 more answers
Other questions:
  • In problem 14 above, how can you decide if your answer is reasonable?
    10·1 answer
  • Which equation has the solutions x = (5 +- 2 \sqrt(7))/(3)?
    12·2 answers
  • 5 less than three times a number is 10
    7·1 answer
  • You placed a 12% down payment on a new home. Given that the amount of the down payment was $42,655.12, determine the price of th
    8·2 answers
  • Help me ASAP PLZZZZZ
    10·1 answer
  • Which of the following angles are supplementary to _1?<br><br> Plsss Help
    13·2 answers
  • Horse Of Course sells "Juan the horse" t-shirts for $23. Due to increased popularity, the store will raise the price by 8%. What
    11·1 answer
  • Point <img src="https://tex.z-dn.net/?f=P%5E1" id="TexFormula1" title="P^1" alt="P^1" align="absmiddle" class="latex-formula"> i
    12·2 answers
  • Plspls help!!
    15·1 answer
  • Use the formula to find the total sum of the interior angles for a polygon with 15 sides.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!