15. 
Add "g" on both sides
Multiply 5 on both sides to get x by itself
x = 5(a + g)
x = 5a + 5g
18. a = 3n + 1
Subtract 1 on both sides
a - 1 = 3n
Divide 3 on both sides to get n by itself
= n
21. M = T - R
Add "R" on both sides to get "T" by itself
M + R = T
24. 5p + 9c = p
Subtract "5p" on both sides
9c = p - 5p
9c = -4p
Divide 9 on both sides to get "c" by itself
c = 
or c = 
27. 4y + 3x = 5
Subtract "4y" on both sides
3x = 5 - 4y
Divide 3 on both sides to get "x" by itself
x = 
x = 
Sin 0 sin 3pi/2 and tan pi
cos pi/2 is -.5
cos 0 is 1
Answer:
5x5 = 25
5x0,5 = 2.5
5x0,03 = 0.15
Adding them makes: 25+2.5+0.15 = 27.75
105° can be expressed as 60°+45°. What we have then is sin(60°+45°). The sum pattern for sin is sin(a)cos(b)+cos(a)sin(b). We will fill in as follows: sin(60)c0s(45)+cos(60)sin(45). Now draw those special right triangles in the first quadrant to get the exact values for each. The sin of 60 is
, the cos of 45 is
, the cos of 60 is 1/2, and the sin of 45 is
. When we put all that together we get
. Simplifying all of that we have
. We can put that over the common denominator that is already there and get
. Not sure if that's simplified enough; you may be at the point in class where you are rationalizing your denominator, but I'm not sure, and if you're not, I don't want to confuse you.
