Answer:
the third one
Step-by-step explanation:
because if we calcul Δ
we get a negative number
Answer:
7. 
8. l=11cm and w=7 cm
9. 
10. 
Step-by-step explanation:
Question 7.
The given expression is:

Expand the parenthesis using the distributive property:

Group similar terms:

Simplify

Divide both sides by -10

Question 8:
Let the width of the rectangle be;
The length of the rectangle is 
The perimeter is given as: 
Given that the perimeter P=36, then:
![36=2[(w+4)+w)]](https://tex.z-dn.net/?f=36%3D2%5B%28w%2B4%29%2Bw%29%5D)

Divide both sides by 2:

Subtract 4 from both sides:



The dimensions of the rectangle is: w=7 cm and l=7+4=11cm
Question 9
Let the number be x.
"5 fewer than the number" is written as 
"5 fewer than a number is at least 12" becomes

Question 10:
Let the number be x.
The quotient of a number and 3 is written as:

The quotient of a number and 3 is no more than 15 is written as;

Answer:
43. I'm not really sure about this one but here's what I got:
The average height of a 4th grader is 58 inches. (Maybe that'll help) Also if it's by the number of kids in the class....I would assume that there are at most 33 kids in the class....I'm not sure what it's asking...sorry :(
46. There are 8 total marbles so if you were selecting a green marble the probability of getting a green marble would be 3/8. If there are 2 blue marbles then the probability would be 2/8 or 1/4
LINK: https://mathbitsnotebook.com/Geometry/Probability/PBIndependentDependent.html
48. In a deck of cards there are 26 black cards and 26 red cards. Number of event occurrences. Total number of trials. For example, if a dice is rolled 6000 times and the number '5' occurs 990 times, then the experimental probability that '5' shows up on the dice is 990/6000 = 0.165. That should help with this one
LINK:
https://explorable.com/experimental-probability
49. Since there are 6 sides and each side is a number 1-6, the probability of rolling a six is 1:6
50. This one is easy if you read the question right. There are no pink marbles....
I'm not that great with graphs
I hope this helped a little....some of the questions I didn't understand.