The volume of a rectangular solid is given by the formula  v  =  lwh,  where  l  is the length,  w  is the width, and  h  is the height. the volume of the rectangular solid in the illustration is  550  cubic centimeters. find the width of the rectangular solid if its length is 10 centimeters and its height is  1 centimeter  longer than twice its wid

This is a case of plugging the given values into the given equation.

The equation we are given is V=lwh where 
V = 550
l = 10
w = ?
h = w  + 1
When plugged in this looks like

Divide both sides by 10

Leaving us with 

at this point i would just check and test number that when multiplied by 1 unit more, it equals 55, I got somewhere between6.9 and 7.9 to 7 and 8 depending on how you are allowed to round. 

Think of it as five or above give it a shove. change the 5 or above to the right to a zero and add one to the number on the left.