Answer:
257 is prime.
Step-by-step explanation:
To evaluate if a number is prime, we just need to evaluate it for the prime numbers that are equal or lesser than the said number's square root.
In this case, √257 = 16.03 so we just need to see if 257 is divisible by <u>2, 3, 5, 7, 11 and 13</u> (the prime numbers that come before 16)
- 257 is odd, so it is not divisible by 2.
- The sum of its digits is 14, therefore, it is not divisible by 3.
- 257 ends in 7, therefore it's not divisible by 5.
- 257/ 7 = 36.71 so it's not divisible by 7.
- 257/ 11 = 23.36 so it's not divisible by 11
- Finally 257 / 13= 19.76 so it's not divisible by 13.
Therefore, 257 is prime.
11 school days are left.
In the attached picture of a calendar, I marked the days the person has left. There are 11.
Answer:Find the distance between the parallel lines m and n whose equations are y = x + 4 and y = x - 6, respectively.
There are several ways to do this...here's one
Let (0, 4) be a point on the first line
Then.......a line with a negative reciprocal slope going through this point will have the equation :
y = -x + 4........so......we can find the intersection of this line with y = x - 6....set both equations equal
-x + 4 = x - 6 add x, 6 to both sides
10 = 2x divide both sides by 2
5 = x
So...using -x + 4, the y value at intersection = -1.......
So...we just need to find the distance from (0,4) to ( 5, -1) =
√[ (5)^2 + (4 + 1)^2 ] = 5√2 ≈ 7.07 units
Here's a pic....AB is the distance with A = (0,4) and B = (5, -1)
Step-by-step explanation:
