So, if k/9=3/9, then k=3, because it is a variable substituting 3. :D Hope I could help!
You can group first two conjunctions and second two:

.
In first brackets you have common

and in second brackets common is 5:

.
Answer:
C. 11
Step-by-step explanation:
Substituting, we have ...
8{80, 19, 11} ?= 88
{640, 152, 88} ?= 88
The value from the set that makes the equation true is x = 11.
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<em>Alternate methods of solution (other than substitution)</em>
It can be easier to make use of your knowledge of factoring:
8x = 8·11
x = 11
Or to make use of your knowledge of numbers (place value):
8·10 = 80
so x will not be very different from 10.
I think the answer is 32% because if you turn 32% into a decimal (which would be 0.32) then multiply it by 25 you would get 8. Which then means if he stopped 8 times and went through 25 intersections then he stopped at 32% of the intersections. I hope this helps :)
The GCF is 5x because 5x goes into all the sets.