The expression's value depends on the signs of a,b,c,d. Each term x/∣x∣ or ∣x∣/x evaluates to either 1 or −1. The last term, 5 abcd/∣abcd∣, is 5 if there's an even number of negative signs among a,b,c,d, and −5 if there's an odd number. To find the maximum value, we choose signs to maximize each part: S1=1, S2=−1, S3=1, S4=-1. This makes abcd>0, so the expression is 1−2(−1)+3(1)−4(−1)+5(1)=1+2+3+4+5=15.
To find the minimum value, we try to make each part as negative as possible, considering the constraint on abcd. The combination S1=1, S2=1, S3=-1, S4=-1, this results in abcd<0. The expression becomes 1−2(1)+3(−1)−4(1)+5(−1)=1−2−3−4−5=−13.
The range of values is the span from the minimum to the maximum. Therefore, the range is 15−(−13)=28.
Regards,
Lucas
Bunuel
For non-zero numbers a, b, c, and d, what is the range of values of the expression \(\frac{|a|}{a} - \frac{2b}{|b|} + \frac{3|c|}{c} - \frac{4d}{|d|} + \frac{5|abcd|}{abcd}\)?
A. 0
B. 13
C. 15
D. 28
E. 30