5y-10 and 2y-6 unless the two are together in which case are they being added or multiplied (the equations).
1) the area of the "side" of the cylinder is A1= pi (4 in).
2) the total area of the circular ends of the cyl. is A2 = 2 pi (2 in)^2 (since the radius of the cyl. is 2 in).
The desired total surface area is A = A1 + A2. Keep "pi;" do not substitute a numerical value for "pi."
Answer:
- after week 7: 4374 pennies
- 486 pennies: after week 5
Step-by-step explanation:
The sequence values have a first term of 6 and a common ratio of 3, so can be described by the formula ...
an = 6·3^(n-1)
This can be rearranged to ...
an = 2·3^n
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When n=7, the value is ...
a7 = 2·3^7 = 4374 . . . . pennies saved after 7 weeks
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To find when there are 486 pennies saved, we can solve the equation ...
486 = 2·3^n
243 = 3^n
log(243) = n·log(3) . . . . . . . take the logarithm
log(243)/log(3) = n = 5 . . . . divide by the coefficient of n
Tabitha will have saved 486 pennies after 5 weeks.
(-2 + 0.8) ÷ (1²-1.3) =
(-1.2) ÷ (1-1.3)
(-1.2) ÷ (-0.3)
= 4