8y+7= y+21
Subtract y from both side
7y+7=21
Subtract 7 from both sides
7y = 14
Divide both sides by 7
Y=2 or A
B. y = 2x-2
14 = 2(8) + b
14 = 16 + b
-2 = b
Answer:

Step-by-step explanation:
Cosine is the adjacent side over the hypotenuse (You can remember sin, cos, and tan by using sohcahtoa or sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite over adjacent). I think a picture would help, too.
I attached a picture of what I think the triangle would look like.
If the picture is right (we're assuming it is) and going with what we're given (the triangle was addressed as triangle XYZ, meaning that <u>angle Y is in the middle and that's the one we'll use</u>).
Looking at my picture then:
.
Answer:
k = 9
Step-by-step explanation:
n = 3, so substitute 3 for n in the equation
k = 3(3)
k = 9