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:
77
Step-by-step explanation:
308 divided by 4=77
4 sides
Option C:
x = 90°
Solution:
Given equation:

<u>To find the degree:</u>

Subtract 1 + cos²x from both sides.

Using the trigonometric identity:




Let sin x = u

Factor the quadratic equation.

u + 2 = 0, u – 1 = 0
u = –2, u = 1
That is sin x = –2, sin x = 1
sin x can't be smaller than –1 for real solutions. So ignore sin x = –2.
sin x = 1
The value of sin is 1 for 90°.
x = 90°.
Option C is the correct answer.
Answer:
it's b
Step-by-step explanation:
you add 7 on both sides to cancel it out. Then isolate x by dividing by 5 on both sides.