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
Let x represent the amount of months she has been saving for.
20x - 60 = 280
Solve for x.
20x - 60 = 280
~Add 60 to both sides
20x - 60 + 60 = 280 + 60
~Simplify
20x = 340
~Divide 20 to both sides
20x/20 = 340/20
~Simplify
x = 17
Therefore, Melanie has saved for 17 months.
Best of Luck!
Answer:
75
Step-by-step explanation:
We can compare by converting Johnny's reading time into the same unit of Jacky's, hours.
There are 60 minutes in an hour, so use this:

15 < 20, so Johnny read faster. This is 5 pages faster per hour than Jacky.