For the equation of the line expressed as Ax + By + C = 0, the value of the slope (m) is calculated by -A / B. For perpendicular lines, the slope of one should be the negative reciprocal of the other. From the choices given, the lines that are perpendicular is Option A.
Answer:
0.7698
Step-by-step explanation:
If you call your random variable 
, then what you are looking for is
because you want the probability of being <em>between 87 and 123.</em>
We need a table with of the normal distribution. But we can only find the table with 
and 
. Because of that, first we need to <em>normalize </em>our random variable:
(you can always normalize your variable following the same formula!)
now we can do something similar to our limits, to get a better expression:
And we transform our problem to a simpler one:
(see Figure 1)
From our table we can see that 
(this is represented in figure 2).
Remember that the whole area below the curve is exactly 1. So we can conclude that 
(because 0.8849 + 0.1151 = 1). We also know the normal distribution is symmetric, then
.
FINALLY:
True. According to the Commutative Property <span>of addition, the numbers could be put in any order and still result in the same answer. </span>
C. 3x + 7 because you can factor out the other 3.
a. 16+4x=4(4+X)
b. 25x+30y=5(5x+6y)
d. 40x-30y = 5(8x-6y)
hope this helps!
