The sum of the first 13 terms is 260
<h3>How to calculate the sum of the first 13 terms ?</h3>
The first term(a) is 2
The common difference(d) is 3
n= 13
The formular is
n/2(2a + (n-1)d)
= 13/2 [ 2(2) + (13-1)3]
= 6.5 [4 + 12(3)]
= 6.5 [4 + 36]
= 6.5(40)
= 260
Hence the sum of the first 13 terms is 260
Read more on sequence here
brainly.com/question/8824658?referrer=searchResults
#SPJ1
The volume of aggregate that she needs to build the patio is 13.18 ft^3
<h3>How many cubic feet of aggregate would she need to build the walkway?</h3>
We know that the backyard is 14ft long, 6 feet wide and 4 inches deep.
Rememeber that:
1ft = 12 in
Then:
4 in = (4/12) ft = (1/3) ft
Then the volume of the backyard is:
V = (14ft)*(6ft)*(1/3 ft) = 28ft^3
Now we know that we have a mix of 4 parts aggregate to 4.5 parts loose cement that need to fill these 28 cubic feet.
Note that:
4 + 4.5 = 8.5
How many times we have 8.5 in 28?
28/8.5 = 3.294
Now for each of these we have 4 parts of aggregate, then the volume of aggregate that we need is:
4*3.294 ft^3 = 13.18 ft^3
The volume of aggregate that she needs to build the patio is 13.18 ft^3
If you want to learn more about volumes:
brainly.com/question/1972490
#SPJ1
For this one I'm going to assume that 4 7a means 4 * 7a...
(8 + 7a) + 4 * 7a =
8 + 7a + 28a =
8 + 35a
If I read it wrong and 4 7a is actually 47a then...
(8 + 7a) + 47a =
8 + 54a =
2(4 + 27a)