what identifies whether the given operation is closed or not closed with respect to each set of numbers.

a. closed
b. not closed

positive integers are under subtraction.

rational numbers are under multiplication.

negative real numbers are under division.

irrational numbers are under addition.

1st is not closed.

2nd is closed

3rd is not closed

4th is closed

Step-by-step explanation:

it's d.

step-by-step explanation:

because: -1(4x + 1y) +2 (1x-3y) distribute each number into the parenthesis.

then you would get: -4x - 1y + 2x -6y combine like terms

and get: 2x -7y

hope my answer has you if not then i'm sorry.

step-by-step explanation:

we are given

since, we have to isolate x on anyone side

so, we can move all x terms on one side

subtract both sides by 2x

add both sides by 9

divide both sides by 4

we get