Answer:
r = -0.1125
Explanation:
It works well to subtract 0.5 and convert the percentage to a decimal. You can find the sum by hand or using a calculator.
r = -0.5 +0.0025 -0.125 +0.51
r = -0.1125
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Comment on the use of a calculator
Many calculators assume that a percentage is to be multiplied by something. If you type this expression into the Google calculator, it will take the % symbol to be an indicator that modulo arithmetic is desired. (It will compute .25 mod -.125 = 0.) So, you need to be aware of how your calculator handles "%". It may be best to do the conversion to decimal before you present the problem to a calculator.