Answer:
31 is a prime number.
How to tell if a number is prime: estimate the square root. In this case, we know the square root of 31 is between 5 and 6 and it isn’t divisible by either of those. If it is divisible by a number higher than it’s square root, the other factor must be lower. Is it divisible by 4 or 2? no, because it isn’t an even number. It’s not divisible by 3, because there’s a remainder of 1 if you try. You’ve eliminated all numbers less than the square root, so it is prime
Answer:
Step-by-step explanation:
We can rewrite 7 as 3+4 then instead of 3*7 we have 3*(3+4).
Then distribute the 3 in the parenthesis 3*(3+4) = (3*3) + (3*4)
Answer:
(1 , 6)
Step-by-step explanation:
the center of the circle is the midpoint of the diameter
Which is the point of coordinates:

Then the center is the point :

9 4/5 as a decimal is 9.8
Answer:
x = 2
Step-by-step explanation:
Given
8(4 - x) = 7x + 2 ← distribute parenthesis on left side
32 - 8x = 7x + 2 ( subtract 7x from both sides )
32 - 15x = 2 ( subtract 32 from both sides )
- 15x = - 30 ( divide both sides by - 15 )
x = 2