To evaluate 1/2yz when y = 3/5 and z = -17/8, we first substitute the given values for y and z into the expression:
1/2(3/5)(-17/8)
Next, we can simplify this by multiplying the fractions:
1/2 * 3/5 * -17/8 = (-3/10) * (-17/8)
To multiply the fractions we multiply the numerators and denominators separately:
(-3/10) * (-17/8) = (-3 * -17)/(10 * 8)
Then we can simplify the numerator by combining like terms:
(-3 * -17)/(10 * 8) = 51/40
So the final result of the expression is 51/40.