For the first question, the answer is 25/14.
Because 14x = 25y Which means x must equal more than y. And 25/14 is the only answer like this.
For the second question, the answer is 30 x 18.
30/5 = 6 18/3 = 6 18 + 18 + 30 + 30 = 96
So, both the perimeter and the ratio is correct with this answer.
For the third question, the first answer is correct.
x < -4 and only a negative number can be less than another negative. Also, the negative must have a higher value to be less than another negative.
For the last question, the last answer is correct. no explanation for this one, it would take too long ;)