Answer:
cos(O) = 39 / 89
Step-by-step explanation:
Given:
ΔOPQ, where
∠Q=90°
PO = 89
OQ = 39
QP = 80
cosine of ∠O?
cos(O) = Adjacent / Hypotenuse
cos(O) = 39 / 89
Let's write that as an equation.
x-8=4x+7
So, you must solve for x by putting all of x on one side then solving for the value of one x.
x-8=4x+7
-8=3x+7
-15=3x
-5=x
Check your work.
(-5)-8=4(-5)+7
-13=-13
Multiplying out the expression, you get
2x^2 -(1/3)x . . . . . . matches selection D
If Lee downloaded 3 more songs than Howard (16 total songs), that means that Howard downloaded 13 songs (total). If Howard downloaded 13 songs, he downloaded 6 more than Erin. Therefore, you would subtract 6 from 13 to get 7.
Answer: Erin downloaded 7 songs
