Answer:
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.
