no for a
yes for B
no for c
that what I think It is opinion could be wrong
The square root 5 is irrational because a square root of a positive number is either an integer or irrational number. Therefore it is irrational.
The decrease was 27%.
Step-by-step explanation:
Old value = $980
New value = $720
Decrease = Old value - New value

Percent decrease = 

Rounding off to near whole percent
Percent decrease = 27%
The decrease was 27%.
Keywords: Percentage, subtraction
Learn more about subtraction at:
#LearnwithBrainly
Let us denote the number of tiles by

.
In the first store, if Darin bought

tiles, he would need to spend:

(measured in $)
In the second store, if Darin bought

tiles, he would need to spend:

(measured in $)
For the cost to be the same at both stores, it means (measured in $)

Moving

over to the left hand side and changing signs:

tiles
Let's check. If he buys 60 tiles in the first store, he spends:
$0.79×60 + $24 = $47.40 + $24 = $71.40
If he buys 60 tiles in the second store, he spends:
$1.19×60 = $71.40
∴
Darin needs to buy 60 tiles for the cost to be the same at both stores.
an equation for a circle has formula
(x-m)² + (y-n)² = r²
where (m,n) is its center
and r is its radius
so, the equation has center (4,3) and radius 4
the equation is derived from the pythagorean theorem