Answer:
86 armed robberies
Step-by-step explanation:
Let a represent the number of armed robberies city A experienced and b represent the number of armed robberies city B experienced.
From the first sentence, we know that a = 2b-18
From the second sentence, we know that a+b=138.
We can solve by substituting the value of a into the second equation to get
(2b-18)+b = 138. Add 18 to both sides and simplify to get 3b = 156. Finally, divide both sides by 3 to get b=52. We can plug this back into the first equation to get a = 2*52 - 18 = 104-18 = 86.
