The unknown number expressed as a mixed fraction is 11 19/20
Let the unknown number be "x"
The sum of the number and 1.75 is expressed as x + 1.75
Half the sum of a number and 1.75 is 1/2(x+1.75)
Equating the result to -5.1 wil give:
1/2(x+1.75) = -5.1
Solve the resulting equation
x + 1.75 = 2(-5.1)
x + 1.75 = -10.2
x = -10.2 - 1.75
x = 11.95
x = 1195/100
x = 11 95/100
Hence the unknown number expressed as a mixed fraction is 11 19/20
Learn more here: https://brainly.com/question/14583740
