Answer:
20 questions
Step-by-step explanation:
Given




Required
Number of questions answered
First, we need to get the total correct marks obtained by Roy
This is calculated by multiplying the correct marks by number of correct answers


Subtract this from the total scores obtained; This gives the total incorrect answer obtained by Roy


Open bracket


Divide this by -2 to get the number of incorrect answers


Add this to the number of correct answers to give the total number of question answered



<em>Hence, Roy answered a total of 20 questions</em>
Hey there!
<u>Use the quadratic formula to find the solution(s). x² + 2x - 8 = 0</u>
x = -4 or x = 2 ✅
<em><u>Quadratic</u></em><em><u> </u></em><em><u>formula </u></em><em><u>:</u></em><em><u> </u></em>ax² + bx + c = 0 where a ≠ 0
The number of real-number solutions <em>(roots)</em> is determined by the discriminant (b² - 4ac) :
- If b² - 4ac > 0 , There are 2 real-number solutions
- If b² - 4ac = 0 , There is 1 real-number solution.
- If b² - 4ac < 0 , There is no real-number solution.
The <em><u>roots</u></em> of the equation are determined by the following calculation:

Here, we have :
1) <u>Calculate </u><u>the </u><u>discrim</u><u>i</u><u>n</u><u>ant</u><u> </u><u>:</u>
b² - 4ac ⇔ 2² - 4(1)(-8) ⇔ 4 - (-32) ⇔ 36
b² - 4ac = 36 > 0 ; The equation admits two real-number solutions
2) <u>Calculate </u><u>the </u><u>roots </u><u>of </u><u>the </u><u>equation</u><u>:</u>
▪️ (1)

▪️ (2)

>> Therefore, your answers are x = -4 or x = 2.
Learn more about <u>quadratic equations</u>:
brainly.com/question/27638369
Answer:
What is the question?
Step-by-step explanation:
I cannot see an attachment.
Answer:
The correct answer is 6.768.
Step-by-step explanation:
(4.23)(1.6) = 6.768
Answer:
Point Y (4, -1) lies on the circle.
Step-by-step explanation:
Distance = √[(x2-x1)² + (y2 - y1)²] = √[(4-1)² + (-1-(-5))²] = √[3² + 4²]= √25 = 5
Point Y (4, -1) lies on the circle, because the distance from the center to this point equals radius of the circle.