You are hiring a limousine. One company charges a $60 reservation fee plus another $15 per hour. A second company charges a $25 reservation fee plus another $20 per hour. Write and solve a linear equation to find the number of hours at which the total cost is the same for both companies.

7 hours

Step-by-step explanation:

Step one:

given data

let the total charges be y and the number of hours be x

Company A charges

$60 reservation fee plus another $15 per hour.

so

y=60+15x1

Company B charges

$25 reservation fee plus another $20 per hour

y=25+20x2

Step two:

equate the 2 expressions above we have

60+15x=25+20x

collect like terms

60-25=20x-15x

35=5x

divide both sides by 5

x= 35/5

x= 7 hours

5

step-by-step explanation:

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

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