Answer:
12
Step-by-step explanation:
you divide 36 by 3 and get z = 13
This is the concept of indices. To re-write the question as instructed we proceed as follows:
b^-6×b^11
according to the rules of indices, when we multiply the number which have the same base, we add their powers. In our case this will be:
b^-6×b^11
adding their powers we get:
b^(-6+11)
=b^5
the answer will therefore be b^5
The brackets are first, then the multiplication
Writing some equations out might help!
1) You know that a is 4/5 of b. This can be written as:

.
To find what b is equal to, multiply both sides by 5/4:

.
A is 5/4 B.
2) You know that a is 1/5 smaller than b. This can be written as:

.
To find b, just add 1/5 to both sides:

.
B is 1/5 bigger than a.
Answer:
8
Step-by-step explanation:
2/7 of 21 is 6 1/3 of 21 is 7. 6+7 is 13. 21-13 = 8