Final answer:
The value of x - y is -27.
Step-by-step explanation:
To find the value of x - y, we need to determine the values of x and y. We are given that the sum of x and y is 153 and the value of the fraction x/y is 0.7.
From the information given, we can set up a system of equations:
x + y = 153
x/y = 0.7
To solve this system, we can multiply both sides of the second equation by y to eliminate the fraction:
x = 0.7y
Substituting this into the first equation:
0.7y + y = 153
1.7y = 153
y = 90
Plugging the value of y back into the second equation:
x/90 = 0.7
x = 0.7 * 90
x = 63
Finally, we can calculate the value of x - y:
x - y = 63 - 90 = -27