Answer:
18
Step-by-step explanation:
Given
x - 1 = 2 ( add 1 to both sides )
x = 3
Then
2x² = 2(3)² = 2 × 9 = 18
have an arithmetic sequence here....to find the common difference, subtract the first term from the second term. 13 - 3 = 10...so basically, ur adding 10 to each number to get to the next number.
before we find s5, we r going to find a5...because we need a5 to use in the sum formula.....a5 is the fifth term, and it is 43
sn = (n (a1 + a5) / 2
s5 = (5 (3 + 43) / 2
s5 = (5 (46)) / 2
s5 = 230/2
s5 = 115 <===
or, for this particular problem, s5 is the sum of the first 5 terms.
3 + 13 + 23 + 33 + 43 = 115.....u can do it this way for s5...but if u were asked to find s20, I suggest using the formula.
Answer:
60,000
Step-by-step explanation:
Let the total people in the household be 100%
If 80 percent of the households have cable television, 60 percent of the households have videocassette recorders and the number of households that have both cable television and videocassette recorders is 'x' percent. The number of households having ONLY cable television will be 80-x while households having ONLY videocassette will be 60-x.
To get x, we will have;
80-x + 60-x + x = 100
140-x = 100
x = 140-100
x = 40
This shows that 40% of the households have both cable television and videocassette.
If there are 150,000 households in the city, then the number of households that have both cable television and videocassette recorders could be 40% of 150,000
= 40/100 × 150,000
= 60,000
Number of households that owns both television and videocassette could be from 60,000.
Answer:
true
Step-by-step explanation: