The expression which shows the amount of money, in dollars Maddie spent on mailing letters in March is 3.7 +0.74 y.
Given Maddie mailed y letters in January. She mailed 3 times as many letters in February. In March she mailed 10 letters more than half of what she mailed in January and February.
Expression is combination of numbers, symbols, fraction, coefficients which are not found in equal to form.
Letters mailed in January=y
Letters mailed in February=3y
Letters mailed in March=10+(y+3y)/2
=10+2y
Amount of mailing of 1 letter=$0.37.
Amount of mailing of letters in March=0.37(10+2y)
=3.7+0.37*2y
=3.7+0.74y
Hence the expression which shows the amount of letters mailed in March is 3.7+0.74 y.
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