Question

1)
C=md+t

The cost C, of a business trip is represented by the equation above, where m is a constant, d is the number of days of the complete trip, and t is the cost of transportation, which doesn't change. If the business trip was increased by 5 days, how much more did the business trip cost than the original trip?

A)5d
B)5m
C)5t
D)d(m-3)
E)m(d-3)
^I got E

2)
4x-3y=9
8x+ky +19

For which value of k will the system of the equations above have no solution?

A) 6
B)3
C)0
D)-3
E)-6
^I do not know

3)A population that starts at 100 and doubles after eight years can be expressed as the following where t stands for the number of years that have elapsed from the start:
A)100 x 2^(t)
B)100 x 2^(t/7)
C)100 x 2^(t-8)
D)100 x 2 ^ (t/8)
E)100 x 2^(16t)
^I got D

If I got a question wrong can you please explain why?

Answer 1

1)
C=md+t

The cost C, of a business trip is represented by the equation above, where m is a constant, d is the number of days of the complete trip, and t is the cost of transportation, which doesn't change. If the business trip was increased by 5 days, how much more did the business trip cost than the original trip?

A)5d
B)5m
C)5t
D)d(m-3)
E)m(d-3)
^I got E
===============================
I did NOT get E
for CHANGE with number of days you use the SLOPE m times the change in umber of days
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2)
4x-3y=9
8x+ky +19

For which value of k will the system of the equations above have no solution?

A) 6
B)3
C)0
D)-3
E)-6
^I do not know
=================================
if the ratio of y to x, which is the SLOPE is the same, the lines will be parallel and never cross
4x-3y=9
8x-6y +19
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3)A population that starts at 100 and doubles after eight years can be expressed as the following where t stands for the number of years that have elapsed from the start:
A)100 x 2^(t)
B)100 x 2^(t/7)
C)100 x 2^(t-8)
D)100 x 2 ^ (t/8)
E)100 x 2^(16t)
^I got D
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YES !!!!
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If I got a question wrong can you please explain why?

Answer 2

2. What is double -3?

you are correct on 3)

you are wrong on 1)

Answer 3

Is 1) B?