Krista and Alexa played balloon darts in a school fair. Krista popped 6 balloons, which is 1 balloon less than Alexa. Complete the working equation that represents the number of balloons, b, that Alexa popped and solve the equation.
a. n-5=13; Alexa popped 18 ballons
b. n+13=5; Alexa popped 8 ballons
c. n-13=5; Alexa popped 18 ballons
d. n+5=13; Alexa popped 8 ballons