The cost, c, of a health club membership is related linearly to its length in months, m. If a 12-month membership costs $260 and an 18-month membership costs $380, which equation can be used to find the cost of a 30-month
membership?

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zwallace30 avatar

zwallace30

02/15/2017

Mathematics

High School

+5 pts

Answered

He cost, c, of a health club membership is related linearly to its length in months, m. If a 12-month membership costs $260 and an 18-month membership costs $380, which equation can be used to find the cost of a 30-month membership?

A) c - 380 = 1/20(30-18)

B) c - 18 = 20(380-30)

C) c - 380 = 20(30-18)

D) c - 18 = 20(30-12)

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dzharvey00

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Treat the c formula as a line. c = sm +b; where m= number of months.

using the two examples:

260 = 12s +b

380 = 18s + b

solve for s & b:

s = 20

b =20

So a 30-month membership is:

c = 20(30) + 20 = 600

Solve C for c and you get 600

Step-by-step explanation:

687.09 dollars       happy now

step-by-step explanation: 6870

1857 times .63 equals 1169.91 subtract that from 1857 you get 687.09

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)