Answer:
7.25
Step-by-step explanation:
Answer:
B'(- 2, 2 )
Step-by-step explanation:
Assuming the dilatation is centred at the origin, then multiply the coordinates of B by the scale factor 2, that is
B(- 1, 1 ) → B'(2(- 1), 2(1) ) → B'(- 2, 2 )
The geometric series with 4th term as 10 and 7th term as 80 has the sum of the first tenth terms as 1278.75.
<h3>How to find sum of terms in geometric series?</h3>
aₙ = arⁿ⁻¹
where
- a = first term
- r = common ratio
- n = number of terms
Therefore,
10 = ar³
80 = ar⁶
Hence,
a = 10 / r³
80 = (10 / r₃) r⁶
80 = 10r³
r³ = 80 / 10
r = ∛8
r = 2
a = 10 / 2³
a = 10 / 8 = 5 / 4
The sum of 10 terms can be calculated as follows:
Sₙ = a(rⁿ - 1) / r - 1
Sₙ = 5 / 4 (2¹⁰ - 1) / 2 - 1
Sₙ = 5 / 4 (1024 - 1) / 1
Sₙ = 1.25(1023)
Sₙ = 1278.75
learn more on geometric series here: brainly.com/question/13592208
