The answer is none. There are no solutions
Start with

Add 2x to both sides:

Subtract 21 from both sides:

Divide both sides by 5. Since it is positive, we don't have to change the inequality sign:

So, the answer is 
Answer:
2/3
Step-by-step explanation:
If we have 'x' students who like math and 'y' students that like science, we can formulate that:
Half of x likes math and science, and also one third of y likes math and science, so:
(1/2) * x = (1/3) * y
x / y = (1/3) / (1/2)
x / y = (1/3) * 2 = 2/3
So the ratio of the number of students who like math to the number of students who like science is 2/3
Answer: 9/15 < 10/15
Step-by-step explanation: 9/15 < 10/15