(3x + 5)° + (10x - 7)° = 180°
13x + (-2) = 180
13x = 180 + 2
13x = 182
x = 14
∠QRT = 3 * 14 + 5 = 42 + 5 = 47°
∠TRS = 10 * 14 - 7 = 140 - 7 = 133°
Answer:
3/10
Step-by-step explanation:
=4/7 + 9/70 - 4/10
=l.C.M of 7 , 70 and 10 =70
=4/7 .10/10 +9/70 -4/10 .7/7
=40/70 +9/70 -28/70
=40+9-28/70
=49-28/70
=21/70
=3/10
Height of the pentagon = 9 ft
Edge of base = 3 ft

s is the length of any side = 3
n is the number of sides = 5
tan is the tangent function calculated in degrees

Volume of the pentagon = area of base (height )
Volume of the pentagon = 15.4852 (9)
Volume of the pentagon = 139.366
Volume of the pentagon = 139.37 cu.ft
This system can be a bit tricky unless you write it out:
(2n + 2)(2n - 2) ~ First you have to take one variable and multiply it to each of the other two variables, like:
2n * 2n ~ And:
2n * -2 ~ This gives you:
4n^2 - 4n
Now we do this with the other:
2 * 2n
2 * -2
4n - 4
Now we combine them both while adding like terms:
4n^2 - 4
Therefore your answer is: A. 4n^2 - 4
(This is due to how when having the positive 4n subtracted by the negative it cancels it out. Leaving us with the remaining two terms left.)
I hope this helps, have a great rest of your day! ^ ^
~Ghostgate