= 2.31(5.82+4.18+90)/ 2.31*0.55
=2.31*100/ 2.31* 0.55
=1*100*0.55
=100*0.55
=55
The sum of the first n terms in a geometric sequence given the first term (a1) and the common ratio (r) is calculated through the equation,
<span>Sn </span>= (<span><span><span>a1</span>(1−<span>r^n</span>) / (</span><span>1−r)
Substituting the known terms,
Sn = (20)(1 - (1/4)^4)) / (1 - 1/4)
Sn = 26.5625
Thus, the sum of the first four terms is 26.5625. </span></span>
Answer: 
Step-by-step explanation:
Answer:
Her final answer should have been x = 1/2.
Step-by-step explanation:
Her 2 errors were that she didn't distribute the 2x to both 4 and -17 and that she made the 13 positive instead of negative when she added 4 and -17 together.
Correct solution:
8(x-3)+7=2x(4-17)
8x-24+7=8x-34x
-17=-34x
The negatives on both sides cancel each other out
x = 1/2
Answer: Choice B. 54degrees
Step-by-step explanation:
Angles 1 4 5 8 are equal and angles 2 3 6 7 are also equal. These two sets of angles of supplementary(you‘d get 180 by adding them).
so
13x+9=180-(5x+9)
by simplifying the equation youll get
18x+18=180
x=9
so angle 7(and therefore angle 6) equals
5*9+9=54
