Answer:
90
Step-by-step explanation:
To find s4 we find sum of values when n=1,n=2,n=3,n=4
given expression is 
n=1 , plug in 1 for n

n=2

n=3

n=4

Sum of all 4 terms = 6+12+24+48=90
Answer:
number 3
Step-by-step explanation:
So the length is 4*28=112mm
The width would be calculated like this:
you draw an equilateral triangle in the middle with sides or 2r(56mm). The based on pythagorean theorem u know that
h=rad(56^2-28^2)=48.497
28+28+h=104.497
The area would be S=l*w which is 11703.7113mm
Answer:
you would need 4 matts
Step-by-step explanation:
Joyce waited 50 minutes waiting for the train
Step-by-step explanation:
divide 60 by 3 cause 3 quarters of an hour is 3/4 then you wanna take half an hour and add that (30 mins) getting 50 minutes