Answer:
Step-by-step explanation:
#8
step #1: <em><u>add $24.94 with $3.82</u></em>
24.94 + 3.82 = 28.76
Step #2: <u><em>subtract </em></u>
$50 - 28.76 = <u>$21.24</u>
rounded part is a semicircle so the area for that is the area of a circle ÷ 2
so
area of the rectangle + (area of the circle ÷ 2) = answer
24 * 14 = 336 = area of the rectangle
14 ÷ 2 = r
(pi * 7^2) ÷ 2
(pi * 49) ÷ 2 = 153.86 ÷ 2 = 76.93 = area of semicircle
336 + 76.93 = 412.93 ft^2 = answer
Answer:
a) 820
b)450
c) -540
d) -294
e) 1440
f) 1425
Step-by-step explanation:
a) it is an arithmetic progression with ratio=4
a1=3,
a2=3+r=3+4=7.....
a20=a1+19r
so a20=3+19*4=3+76=79
S=(a1+an)*n/2 where n=20
so S=(3+79)*20/2=820
b) a15=a1+14*r=2+14*4=2+56=58
S=(a1+a15)*15/2=(2+58)*15/2=60*15/2=30*15=450
It is the same formula for all the exercises
S=(a1+an)*n/2 , where n is the number of terms
c) a40=30+39*(-3)=30-87=-57
So S=(30-57)*40/2=-540
d) a14=5+13*(-4)=5-52=-47
S=(5-47)*14/2=-42*14/2=-42*7=-294
e) it is 5+7+9+......+75
nr of terms = (an-a1) :r+1=(75-5):2+1=36
S=(5+75)*36/2=36*40=1440
f) ratio=7-4=3
the same formula for n= (91-4):3+1=87:3+1=29+1=30
S=(4+91)*30/2=95*30/2=2850/2=1425
