Answer:

-12x = 60
Step-by-step explanation:
This is the type of problem that you just have to do a bunch of times until you get it right -- I don't think there's anything I can tell you that'll help you immediately. Ask for your teacher for more exercises of this sort or look it up online.
Good luck!
Answer:
A
Step-by-step explanation:
If two nonadjacent angles formed by two intersecting lines = Vertical angles= congruent
Then
Two non adjacent angles formed by two intersecting lines are congruent
Answer: i - j - k
Step-by-step explanation:
Taking the cross product between two vectors will give you a third vector that is orthogonal(perpendicular) to both vectors.
<1,1,0> x <1,0,1>
![det(\left[\begin{array}{ccc}i&j&k\\1&1&0\\1&0&1\end{array}\right] )](https://tex.z-dn.net/?f=det%28%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Di%26j%26k%5C%5C1%261%260%5C%5C1%260%261%5Cend%7Barray%7D%5Cright%5D%20%29)
the determinate of the matrix: <1,-(1),-1>
or: i - j - k
Answer:
(examples) n = 2
n = 3
n = 4
Step-by-step explanation:
to demonstrate, all you do is select a number to represent 'n' and plug it in.
so for example, n = 2:
2(2) + 3(2) = 5(2)
4 + 6 = 10, which is true.
Answer:
27
Step-by-step explanation:
15x-31 = 9x+11
6x-31 = 11
6x = 42
x = 7
15x -31 + 9x + 11 + s = 180
15(7) -31 + 9(7) + 11 + s = 180
105 - 31 + 63 + 11 + s = 180
153 + s = 180
s = 27