Answer:
27. 98% of 15 is 14.7 (rounding to the nearest tenth, this would be 15)
28. 250% of 25 is 62.5 (rounding to the nearest tenth, this would be 63)
29. 108% of $50 is $54
30. 75.2% of 130 is 97.76 (this would be 98)
Step-by-step explanation:
the sum of all interior angles in a polygon is
180( n - 2)
n = number of sides
now, this polygon is a quadrilateral, so it has 4 sides, so it's total is just 180( 4 - 2) = 360.

Answer:
Irrational numbers are not closed under addition.
Step-by-step explanation:
Irrational numbers are the numbers that cannot be expressed in the form of a fraction
. In other words we can say that irrational number,s decimal expantion does not cease to end.
The closure property of addition in irrational numbers say that sum of two irrational number is always a rational number, But this is not true. It is not necessary that the sum is always irrational some time it may be rational.
This can be understood with the help of an example:
let (2+√2) and (-√2) be two irrational number. Their sum is (2+√2)+(-√2) = 2, which is clearly a rational number.
Hence, irrational numbers are not closed under addition.
Answer:
a+b = 4
Step-by-step explanation:
3(a + b)^2 = 81
(a + b)^2 = 27
a + b = sq rt 27
a + b =
· 
a + b = 3