Answer:
3 feet by 7 feet
Step-by-step explanation:
perimeter = 20 feet
area = 21 feet²
If the desk is a rectangle:
perimeter = 2l + 2w = 2 (l+w) = 20
2 (l+w) = 20 , divide both sides by 2
l+w = 10
area = l · w = 21
What numbers we know that have sum as 10 and their product as 21?
l + w = 10
l · w = 21
factors of 21 are 1,3,7
3+7 = 10
3 ·7 = 21
The dimensions of the desk could be 3 feet by 7 feet.
Answer:
element remained after 14 minutes = = 7.091 g =~ 10 g
Step-by-step explanation:
After every minute the amount remained will be
(100 - 26.9 ) % i.e. 73.1 %
which is 0.731 times as much as the amount was at the start.
if the number of minutes passed is represented by t the function f(t) represents the mass of element remaining our equation will be
f(t) = 570( 0.731) ^ t
t= 14 minutes
f(14) = 570 ( 0.731) ^ 14
= 7.091 g =~ 10 g
The answer of this problem is A because 3 times 21 is 63 and then you plus 1
which is 64
