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.
Answer:
Step-by-step explanation:
Perimeter is simply length + width. They gave us that the length is 2 feet plus 2 times the width:
Subtract 2 from both sides to get 23 = 2w + w
Combine like terms to get 23 = 3w
Divide by 3 to get 
feet
The answer to this equation is
x= (1/4)
4,000,000 and 20,000,000 miles²
let x be the area of one desert then 5x is the area of the other
sum = x + 5x = 24,000,000
6x = 24,000,000
divide both sides by 6
x = 4,000,000
one desert is 4,000,000 miles²
and the other is (5 × 4,000,000)= 20,000,000 miles²
