What is the difference between the area of figure a and the area of figure b each grid square represents one square

Step-by-step explanation:

for question 5 )  

we know that  x-5 = 6   because I'm pretty sure outside of the question we are told that the rectangles  are similar and therefore,  we can say the above

x-5 = 6

add 5 to both side

x = 11

for question 6)

30 is   of 36, so use that on the remaining given side

  * 15 = 12.5

then thats what the other side of the bigger shape is

12.5 = x + 6

minus 6 from both sides

6.5 = x

by the way,  notice that they have used a variable "x" for both 5 & 6 which is named the same but has a different value  in each problem.  X is the name of the variable for each problem, but doesn't have any meaning once outside of each of the problems.  It's just confusing to use the same named variable at times.  something like xy   and xz ,  might have been better names.    anyway  :)