Question 790700
to solve for d, try to get the d by itself on one side of the equal sign.
you can do this by getting rid of the 1 and 5 term on the same side as the d.
to get rid of the -1 we will add 1 to both sides 

5d-1= -11
 +1    +1

5d= -10 

now to get rid of the 5 we have to divide it away, and whatever we do to one side of the equal sign we have to do to the other side 

5d/5 = -10/5

d= -2   * we got the -2 because 5 goes into 10 2 times