Answer:
740
Step-by-step explanation:
The n th term of an arithmetic series is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₃ = 7 and a₇ = (3 × 7) + 2 = 21 + 2 = 23 , then
a₁ + 2d = 7 → (1)
a₁ + 6d = 23 → (2)
Subtract (1) from (2) term by term
4d = 16 ( divide both sides by 4 )
d = 4
Substitute d = 4 into (1)
a₁ + 2(4) = 7
a₁ + 8 = 7 ( subtract 8 from both sides )
a₁ = - 1
The sum to n terms of an arithmetic series is
= 
[ 2a₁ + (n - 1)d ] , thus
= 
[ (2 × - 1) + (19 × 4) ]
= 10(- 2 + 76) = 10 × 74 = 740
I'm doing 3
For 3, using a table is very similar to a double number because the numbers are matching up in both ways.
On the bottom of a double number line we have like, for example,-- the bottom of the double number line would have batches. And its 1, 2, 3 ,4 , etc.
And on a table, it would be the same, the numbers on both diagrams have the same methods, have same way of lining things up but they're just drawn differently.
Hope this helped!
Answer:
3
Step-by-step explanation:
every repeating decimal will be a rational number
Answer:
You can make 64 different sums (which includes a sum of $0 using none of the coins).
Step-by-step explanation:
The number of sums you can make is equal to:
⁶C₀ + ⁶C₁ + ⁶C₂ + ⁶C₃ + ⁶C₄ + ⁶C₅ +⁶C₆ = 1 + 6 + 15 + 20 + 15 + 6 + 1 = 64
