How are these numbers different 1.5 and 15

1.5 and 15 are different because the first number has a decimal point

Step-by-step explanation: if 15 was divided by 10, it would equal 1.5

- 1.613 = -1.6 or -1.61

-1.522 = -1.5 or -1.52

0.587 = 0.6 or 0.59

3.079 = 3.1 or 3.08

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value