Answer:
76
Step-by-step explanation:
Assuming that all exams have the same weight, in order to achieve an average score of 80, the sum of all scores must equal 4 x 80. Therefore, the grade Jose needs in his last exam is:

Jose needs to score a 76 in his last exam to have a mean of 80.
<h3>
Answer: E. 45/4</h3>
===========================================
Work Shown:
Because we have similar triangles, we can form the proportion below to isolate x.
(AC)/(BC) = (CD)/(AC)
(15)/(20) = (x)/(15)
15*15 = 20x .... cross multiply
225 = 20x
20x = 225
x = 225/20
x = (5*45)/(5*4)
x = 45/4
Answer:
A is the answer on edgdenuity
Step-by-step explanation:
Answer:
see explanation
Step-by-step explanation:
(3)
Given cosΘ = - 
Then by Pythagoras' theorem the third side is 3 ( 3,4, 5 triangle )
Since Θ in second quadrant then sinΘ > 0
sinΘ = 
Using the trigonometric identity
sin2Θ = 2sinΘcosΘ, then
sin2Θ = 2 ×
× -
= - 
(4)
Using the trigonometric identity
cos(x - y) = cosxcosy + sinxsiny
note cos15° = cos(45 - 30)°
cos(45 - 30) = cos45cos30 + sin45sin30
= (
×
) + (
×
)
= 