Find the slope of the first line, that is the difference of the y’s over the difference of the x’s. This way: 2-5/2-5=-3/-3 which equals 1
Now find the slope of the second line 2-(-6)/-5-3
=8/-8
=-1
The slopes are opposite reciprocal ( you could also say that the product of the 2 slopes equals -1) therefore the lines are perpendicular.
1a+18=7a
18=7a-1a
18=6a
6a=18
a=18/6
a=3
<u>Answer:</u> The value of 15th term is 0
<u>Step-by-step explanation:</u>
The nth-terms of an AP is written as
where,
a = first term
n = number of term
d = common difference
5th tem will be = 
11th tem will be = 
15th tem will be = 
The given ratio between 5th and 11th term is 5 : 2
Taking the ratios:

Hence, the value of 15th term is 0
Answer:
Commutative property
Step-by-step explanation:
Answer: x=5/3
Step-by-step explanation:
For this problem, you want to solve for x. You first distribute, get all like terms to one side, and then sovle for x.
2(x+3)=5(x-1)+6
2x+6=5x-5+6. (combine like terms)
2x+6=5x+1 (move all like terms to one side)
5=3x (divide to solve for x)
x=5/3