Answer:
-0.5 is not a solution
2 is a solution
Step-by-step explanation:
To check if something is a solution of the equation, you need to substitute the value in place of the variable
15 + 2y = -12 - 4y
15 + 2(-0.5) = -12 - 4(-0.5)
15 - 1 = -12 + 2
14 ≠ -10 ∴ -0.5 is not a solution
5 - 2(3x + 5) = 3 - 10x
5 - 2[3(2) + 5] = 3 - 10(2)
5 - 2(6 + 5) = 3 - 10(2)
5 - 12 - 10 = 3 - 120
-17 = -17 ∴ 2 is a solution
Yes! Just like if I told you three shapes, and that one and two are circles, and then I told you the third was the same as the second, they would all be circles!
We have

So

The rational term vanishes as <em>x</em> gets arbitrarily large, so we can ignore that term, leaving us with

and this happens if <em>a</em> = 1 and <em>b</em> = -1.
To confirm, we have

as required.
A rational number is a number that is not repeating. So a rational number can be 5 or 2.3314. But Pi is irrational. So is 1/3 and 2/3 because in decimal form they are repeating. Which means they will go on forever which makes them irrational.