The output would be -9.
If you substitute -10 in for x, the equation becomes:
Y = (3/2)(-10) + 6.
First solve for (-3/2)(10).
(-3/2)(10) = -15.
This is negative because a negative number multiplied by a positive number will equal a negative number.
Then add 6 to -15.
-15 + 6 = -9.
Therefore, when the input is -10, the output is -9.