The formula is
YC x YD = AY x YB
fill in what we know:
18 x 6 = 9 x YB
108 = 9 x YB
YB = 108 / 9
YB = 12
The answer would be 1/15.
Find the greatest common multiple of each fraction, then add them. You will get 1/15 out of it.
I think it’s the first one is not sure tho
Any transformation involving change of scale will not result in a congruent figure. Rotations and reflections and translations maintain congruence.
Try this solution:
let the unknown two-digits number be 'xy'.
Then it is possible to write any two-digit number as 10x+y, where x - the tens digit and y - the unit digit.
Using the rule described above the phrase 'the tens digit of a number is twice the units digit' may be written as x=2y.
Using the same rule the phrase 'if the digits are reversed, the new number is 36 is less than the original number' may be written as (10x+y)-(10y+x)=36.
These two equations may be resolved as system of two equations:

Check: the original number is 84, the new number is 48; difference is 84-48=36.
answer: 84