Sorry but i only know the answer to number 3
<span>
A rational number is a number that can be written as a fraction where numerator and denominator are both integers (and the denominator is not zero).
Since 0.57 = 57/100, so the number 0.57 can be written as a fraction where the numerator (57) and denominator (100) are both integers. </span>
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:
c.132
Step-by-step explanation:
so we are given the diameter which is 42m **the diameter is the straight line that passes through the middle of the circle**
but in order to find the circumference we need to find the radius **the radius is always half (1/2,0.5) of the diameter**
so we have to divide 42/2 which equals 21
now we need to set up the formula;
c=2πr/c=2xπxr **when unknown variables such as 'r' are next to another mathematical numeral such as the pi symbol you don't really have to but the multiplication symbol between them**
c=2π21
=131.946891451
and in your case, it seems we must round to the tenths place so the nine then "becomes a ten" and you're left with 132
good luck :)
i hope this helps
have a good one !!
Basically expand
use FOIL (a way to remember distributive property)
first outer inner last
that is th eorder to multiply them
First: x times 2x=2x²
Outer: x tmes 9=9x
Inner: -8 times 2=-16x
last: -8 times 9=-72
add them
2x²+9x-16x-72
2x²-7x-72