The student would have to score 100% on their next test to brung their average up to 90. Here is why;
90+84+86=260
(260+?)/4=90
(260+100)/4=90
360/4=90
This is done to get the mean (or average) of a group of numbers by adding all the numbers and dividing by the amount of numbers you added together. Here it is divided by 4 because of the three tests he has taken and the test he will take.
Answer:

Step-by-step explanation:
The given rational equation is

The Least Common Denominator is

Multiply each term by the LCD.

Simplify;


Expand;

Group similar terms;


Divide by -8.

William needs 102.6 fencing in all because 76.9 plus 25.7 equals 102.6, hope this helps!
Answer:
$2
Step-by-step explanation:



Therefore, each raffle ticket cost $2.