Question

Complete the following problems. Please show your work.

Answer 1

Answer:

see explanation

Step-by-step explanation:

(1)

Using the relationship

distance (d) = speed (s) × time (t)

The freight train leaves the station 1 hour earlier than the passenger train, so

d = 40(t + 1) ← Freight train

d = 50t ← Passenger train

We require to find when they are at the same distance from the station, then equating the 2 equations

50t = 40(t + 1) ← distribute

50t = 40t + 40 ( subtract 40t from both sides )

10t = 40 ( divide both sides by 10 )

t = 4

The passenger train will overtake the freight train after 4 hours

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(2)

let l represent length, then width = l - 32

perimeter (P) = 2l + 2w = 290, that is

2l + 2(l - 32) = 290 ← distribute and simplify left side

2l + 2l - 64 = 290

4l - 64 = 290 ( add 64 to both sides )

4l = 354 ( divide both sides by 4 )

l = 88.5 and w = 88.5 - 32 = 56.5

Then dimensions are 88.5 yards by 56.5 yards

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(3)

Plan A : 100 + 15n

Plan B : 25n

When is Plan A better than Plan B , that is

100 + 15n > 25n ( subtract 25n from both sides )

100 - 10n > 0 ( subtract 100 from both sides )

- 10n > - 100

Divide both sides by - 10, reversing the symbol as a result of dividing by a negative quantity.

n < 10

Plan A is better when number of hours (n) is less than 10

Answer 2

Answer:

3. Jeanette can be paid in one of two ways for painting a house. : Plan A; $100 plus $15 per hour; Plan B: $25 per hour. Suppose that a job takes n hours to complete. For what values of n is Plan is Plan A better for Jeanette?