Step-by-step explanation:
an = 2n^2 - 3 · Anonymous. -1, 5, 15, 29, 47, ... an = 2 n^2 - 3.
Answer:
1655
Step-by-step explanation:
Note the common difference d between consecutive terms of the sequence
d = - 1 - (- 4) = 2 - (- 1) = 5 - 2 = 8 - 5 = 3
This indicates the sequence is arithmetic with sum to n terms
=
[ 2a₁ + (n - 1)d ]
Here a₁ = - 4, d = 3 and n = 90, thus
=
[ (2 × - 4) + (89 × 3) ] = 45(- 8 + 267) = 45 × 259 = 1655
Answer:
12.90= .90+ 2x
12=2x
6=x
Each bag of books cost was $6
Step-by-step explanation:
sqrt(5x)×(sqrt(8x²) - 2×sqrt(x)) =
sqrt(5x × 8x²) - 2×sqrt(5x × x) =
sqrt(40x) × x - 2x × sqrt(5) =
2x×sqrt(10x) - 2x×sqrt(5)
therefore, the last option is correct.