We know that
a(n)=4n+1
To find the sum of the first n<span> terms of an arithmetic series
use the formula
</span><span><span>Sn</span>=<span>n(<span>a1</span> + <span>an</span>)/2
</span></span>a1--------------> is the first term
an--------------> is the last term
n--------------- > <span>is the number of terms
</span>we have that
a1------------> 4*(1)+1=5
a30----------> 4*(30)+1=121
n------------- > 30
S30=30*(5 + 121)/2=1890
the answer is 1890
Answer:
B or D
Step-by-step explanation:
Answer:
Step-by-step explanation:
The sides are in the ratio 1:2:3, so the lengths of the sides are 1x, 2x, 3x.
1x + 2x + 3x = 48'
6x = 48'
x = 8'
The lengths of the sides are 8', 16', 24'
Its simple, the expression is 7+x and it does not have an equal sign since it is not an equation
