Question

a system of equations is shown below: equation a: 2c = d − 8 equation b: c = 3d 8 which of the following steps should be performed to eliminate variable d first? multiply equation b by 2. multiply equation a by 2. multiply equation b by 3. multiply equation a by −3.

Answer 1

If you would like to know which of the following steps should be performed to eliminate variable d first, you can find this using the following steps:

equation a: 2c = d - 8      /*(-3)
equation b: c = 3d + 8
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-6c = -3d + 24
c = 3d + 8
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-6c + c = -3d + 24 + 3d + 8
-5c = 32
5c = -32
c = -32/5

The correct result would be: multiply equation a by −3.