Answer:
Rule of 9 : an integer is divisible by 9 if and only if the sum of its integers is divisible by 9.
Proof :
Let us consider a number x such that,
Where, 
are the the digits of the number x,
So, we can write,
Let,
Since, a number is in the form of 
, where k is an positive integer, is always divisible by 9,
⇒ 
are divisible by 9.
⇒ x-S is divisible by 9,
⇒ If S is divisible by 9 ⇒ x must divisible by 9,
Or if x is divisible by 9 ⇒ S must divisible by 9.
Hence, proved...
Answer:
See below
Step-by-step explanation:
The equation has no solution because no matter what the value we plug for 
in the equation, it will not be true and will lead to a contradiction. This is the meaning of not having a solution.
Answer:
y = -x + 15
Step-by-step explanation:
y = x-2
slope = 1
perpendicular line slope = -1
pass point (10, 5)
y intercept = y - mx = 5 - (-1)x10 = 15
equation: y = mx + b
y = -x + 15
To find the unit rate, you have to divide 240 by 2.5.
240/2.5 = 96
The answer is = 96 kilometers per hour.
