13 times an unknown number added 72 equals -23 times the unknown number

X=2

Step-by-step explanation:

Let the unknown number be x

13*x+72=-23*x

13x+72=-23x(collect like terms and add -72 to both sides)

13x+72-72=-23x-72=13x=-23x-72(collect like terms again and add +23x to both sides)

13x+23x=-23x-72+23x=36x=-72

36x=-72(divide both sides by the coefficient of x;36 on both sides)

36x/36=-72/36

X=2.

3

Step-by-step explanation: