Is this right and can someone show me the explanation plz?and how to do the problem I have to show my work

yes it is.

x = 4 and y = -3

Step-by-step explanation:

Solve simultaneously using elimination method:

equation 1 - equation 2

3x + y = 9 equation 1

-2x + y = 5 equation 2

x = 4

plug 4 into any of the 2 equations and solve for y.

3(4) + y = 9

12 + y = 9

12-12 + y = 9-12

y = -3

ratio is 2 : 9

the answer is three

13.5 : 3

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)