Answer
Find out the what is the surface area of the pyramid .
To proof
Formula
Surface area of a square pyramid

Where a is the base edge and h be the height .
As given
A square pyramid has a base with side lengths each measuring 40 inches. The pyramid is 21 inches tall, with a slant height of 29 inches.
i.e Base edge = 40 inches
Height = 21 inches
Put values in the above formula

solving



= 1600 + 80 × 29
= 3920 inches²
Therefore the surface area of the pyramid is 3,920 inches²
Hence proved
Answer:
9. x>-4 or x≥1
10. a<2 or a≥-5
11. v≤7 or v≥-4
12. k≥5 or k<8
13. n>6.8 and n≤9
Step-by-step explanation:
9. -2x-7>1
-2x>8
x>-4
x-2≥-1
x≥1
10.a/-2 <-1
a<2
-4a+3≥23
-4a≥20
a≥-5
11. 6v+38≤-4
6v≤-42
v≤7
2(v+3)≥-2
2v+6≥-2
2v≥-8
v≥-4
12. 4(1-k)≥-16
4-4k≥-16
-4k≥-20
k≥5
7-6k<-41
-6k<-48
k<8
13. 10n-9>-59
10n>-68
n>6.8
n-6≤3
n≤9
Find an explicit formula for the geometric sequence −1,−7,−49,−343,...-1\,,-7\,,-49\,,-343,... −1,−7,−49,−343
umka21 [38]
So we see it times 7 each time
starting with -1
geometric
an=a1(r)^(n-1)
a1=first term
r=common ratio
first term is -1
r=7

is the formula
also can look like this:
<u>Answer:</u>
- The cost of 1 dozen doughnut is $6 and the cost of a dozen croissant is $10.
<u>Step-by-step explanation:</u>
<u>We know that:</u>
- D = Cost of a dozen doughnut
- C = Cost of a dozen croissant
- 10D + 7C = 130
- 6D + 4C = 76
<u>Work:</u>
6D + 4C = 76
7(6D + 4C = 76)
42D + 28C = 532
- 40D - 42D = 520 - 532
- => -2D = -12
- => 2D = 12
- => D = 6
<u>Now, let's substitute the value of D into the first equation.</u>
- 10D + 7C = 130
- => 10(6) + 7C = 130
- => 60 + 7C = 130
- => 7C = 70
- => C = 10
Hence,<u> the cost of 1 dozen doughnut is $6 and the cost of a dozen croissant is $10.</u>
Hoped this helped.

Answer:
<h2>x = 1/4 and y = -2</h2>
Step-by-step explanation:
