Question

Difficulty: MediumSolving Linear Equations

The length LL, in centimeters, of a copper rod at a temperature of TT degrees Celsius can be modeled by the linear equation L=150.04+0.012TL = 150.04 + 0.012T. If the length of the rod is measured to be 150.40150.40 centimeters, what is its temperature in degrees Celsius?

Answer: 30 degrees Celsius

Answer

The temperature of the rod is 30 degrees Celsius.
The correct answer is 30. By substituting the given length of 150.40150.40 centimeters into the equation for LL, we get 150.40=150.04+0.012T150.40 = 150.04 + 0.012T. Subtracting 150.04150.04 from both sides gives 0.36=0.012T0.36 = 0.012T. Finally, dividing both sides by 0.0120.012 yields the temperature T=30T = 30 degrees Celsius.

Step-by-Step Solution

1
Substitute the measured length L=150.40L = 150.40 into the equation.
150.40 = 150.04 + 0.012T
To set up the equation with the given value for length.
2
Subtract 150.04 from both sides of the equation.
0.36 = 0.012T
To isolate the variable term containing TT.
3
Divide both sides of the equation by 0.012.
T = 30
To find the temperature TT.

Key Concept

Solving a multi-step linear equation involving decimals
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