Ok this is a pretty easy one.
2=22
3=20
4=18
For sake of convenience, reverse the series, then it would be:
21,19,17.....7
a=21, d = -2,
s(4) = 4/2 (21+15)
s(4)=2(36)
s(4) = 72
Answer:
see below
Step-by-step explanation:
360 - 56 - 106 = 198 degrees
198 / 3 = 66 degrees per unit
angle f = 132 degrees
angle g = 66 degrees
Answer:
16) 
17) y = -x - 4
18) y = -2x - 1
19) y = -2x
20)
Step-by-step explanation:
With the two points you find the slope using 
Then using that slope, plug the slope in with one of the points values of x and y into the point slope formula, and smiplify that into the y-intercept formula.
25 girls and 50 boys!!
49 divided by 7 = 7.
So there were 7 adults.
49 + the 1 it mentioned = 50 boys
50 divided in half = 25 girls.
50+25+7 = 82.