Answer:
a) possible progressions are 5
b) the smallest and largest possible values of the first term are 16 and 82
Step-by-step explanation:
<u>Sum of terms:</u>
- Sₙ = n/2(a₁ + aₙ) = n/2(2a₁ + (n-1)d)
- S₂₀ = 20/2(2a₁ + 19d) = 10(2a₁ + 19d)
- 2020 = 10(2a₁ + 19d)
- 202 = 2a₁ + 19d
<u>In order a₁ to be an integer, d must be even number, so d = 2k</u>
- 202 = 2a₁ + 38k
- 101 = a₁ + 19k
<u>Possible values of k= 1,2,3,4,5</u>
- k = 1 ⇒ a₁ = 101 - 19 = 82
- k = 2 ⇒ a₁ = 101 - 38 = 63
- k = 3 ⇒ a₁ = 101 - 57 = 44
- k = 4 ⇒ a₁ = 101 - 76 = 25
- k = 5 ⇒ a₁ = 101 - 95 = 16
<u>As per above, </u>
- a) possible progressions are 5
- b) the smallest and largest possible values of the first term are 16 and 82
Answer:58
Step-by-step explanation:
20×4 then 2×7 then add both answers u get 58
Answer:
268 cm
Step-by-step explanation:
A P E X
Answer:
Depends on domain of x, could be
-√(y+10)/7; √(y+10)/7 or no solutions
Step-by-step explanation:
You need to solve it for x:
y=7x^2-10
7x^2=y+10
x^2=(y+10)/7
In order for this equation to have an inverse, you need to check the domain of x. There needs to be only one solution for x^2=(y+10)/7 - either positive or negative, depending on the domain.