If #S=(n(a+1))/2# what is #n#? Algebra Expressions, Equations, and Functions Variable Expressions 1 Answer Alan P. Mar 19, 2017 #n=(2S)/(a+1)color(white)("XXX")#provided #(a+1)!=0# Explanation: Given #color(white)("XXX")S=(n(a+1))/2color(white)("XX")#...at least that's how interpreted the question. #(n(a+1))/2 = Scolor(white)("XXXX")#because we usually like to have the variable we are solving for on the left. #rarr n(a+1) = 2Scolor(white)("XXXX")#after multiplying both sides by #2# #rarr n= (2S)/(a+1)color(white)("XXXX")#after multiplying both sides by #(a+1)# and with the assumption that #a!=-1## Answer link Related questions How do you write the variable expression for: a quotient of 2 and the sum of a number and 3 ? What are variables? What are variable expressions? How do you write variable expressions? How do you evaluate variable expressions? How do you simplify the expression #3x-x+4#? How do you write a quotient of a number and 6 as an expression? How do you evaluate the expression #2x+1# for #x=1#? How do you write a product of a number and 2 as an expression? How do you write 5 less than 2 times a number as a variable expression? See all questions in Variable Expressions Impact of this question 460 views around the world You can reuse this answer Creative Commons License