Q. The value of x is decreased by 39%. Which expression does NOT represent this situation?39xx−0.39x0.61x1x−0.39x
Understand the problem: Understand the problem.Decreasing a value by 39% means that the new value is 100%−39%=61% of the original value. Therefore, the correct expression should represent 61% of x.
Convert to decimal: Convert the percentage to a decimal to use in the expressions.61% as a decimal is 0.61. So, the correct expressions should be equivalent to multiplying x by 0.61.
Evaluate first expression: Evaluate the given expressions to see which one does NOT represent 61% of x. The first expression is "39×x". This represents 39 times x, not 61% of x.
Check second expression: Check the second expression x−0.39x. This expression can be simplified to 0.61x because x−0.39x=1x−0.39x=0.61x. This represents 61% of x.
Check third expression: Check the third expression "0.61×". This expression directly represents 61% of x, which is the correct representation of the decrease.
Check fourth expression: Check the fourth expression 1x−0.39x. This expression simplifies to 0.61x as well, because 1x−0.39x=0.61x. This also represents 61% of x.
Determine incorrect expression: Determine which expression does NOT represent the decrease of x by 39%. The expression "39x" does not represent a 39% decrease of x. It represents 39 times x, which is not the same as 61% of x.
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