Let [tex]m[/tex] be the number of months. Since Club A charges $11 only one time and charges $11 per month, the total charge after [tex]m[/tex] months is [tex]\$11 + \$11m[/tex]. Similarly, the total charge after [tex]m[/tex] months for Club B is [tex]\$27 + \$7m[/tex].
Since we want to find after how many months the two clubs charge the same amount, we can set those two expressions equal to each other and solve:
[tex]\$11 + \$11m = \$27 + \$7m[/tex]
[tex]\$4m = \$16[/tex]
[tex]\bf m = 4[/tex]
So, Club A and Club B will charge the same amount after 4 months. To find how much they charge, just plug [tex]m[/tex] back into one of the original equations:
[tex]\$11 + \$11m = \$11 + \$11(4) = \bf \$55[/tex]