Answer:
first and third digit are the same.
not prime numbers,
191 yes but 484 no.
172.9
You find it by multiplying each side of the triangle by the height (9) and adding the results together.
A(lateral) = 8 * 9.1 + 3 * 9.1 + 8 * 9.1
= 72.8 + 27.3 + 72.8
= 172.9
2 less than (3 times a number) is the same as (the number plus 10)
2 less than (3*x) = (x + 10)
3x - 2 = x + 10
From here, you solve! :)
3x - 2 - x = x + 10 - x
2x - 2 = 10
2x - 2 + 2 = 10 + 2
2x = 12
2x / 2 = 12 / 2
x = 6
Hope this helps! :)