A telecommunications company is installing fibre optic cables across a city. The cost, C dollars, of installing x metres of cable is modelled by the equation C = 15x + 2400. What does the value 2400 represent?

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Question

A telecommunications company is installing fibre optic cables across a city. The cost, C dollars, of installing x metres of cable is modelled by the equation C = 15x + 2400. What does the value 2400 represent?

Accepted Answer

The fixed installation cost — Award 1 mark for recognising that 2400 is the y-intercept (constant term) representing the initial fixed cost before any cable is installed. A is incorrect — 15 is the cost per metre. C is incorrect — this misinterprets the constant term as a total. D is incorrect — 15 is the gradient.

Answer

The cost per metre of cable

Answer

The total cost for 15 metres

Answer

The fixed installation cost

Answer

The gradient of the line

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