Question

Calculate much net Work per unit charge would it take to move a particle from a -15 V potential 

to a +10 V potential? Does the path of the motion matter?

Answer 1

Now we know that

$q=1C$

$V_1=-15V\\V_2=10V$

$$∆V=V_2-V_1=(10+15)=25V$$

Work

$W=q∆V$

$W=1\times25=25J$