SOLUTION: What is the inherent meaning and justification of cross-multiplication as it applies to solving an inequality?
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-> SOLUTION: What is the inherent meaning and justification of cross-multiplication as it applies to solving an inequality?
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You can put this solution on YOUR website! Cross multiplication used to be frowned on by teachers because you aren't obviously doing the same thing to both sides.
3/4=x/7
The proper way is to
multiply both sides by 4
3*4/4=x*4/7
3=4x/7
then multiply both sides by 7
3*7=4x*7/7
simplify
3*7=4x
but with cross multiplication we skip the step of showing that we multiply one side by each number.
3/4=x/7
we jump right to the result
3*7=4x
It is shorter and therefore preferred by students.
However there is more chance of errors and not really understanding what you are doing and why.
