Zoe is comparing two local yoga programs. Yo-Yoga charges a $35 registration fee and $90 a month. Essence Yoga charges a registration fee of $75 and $80 per month. After how many months will the 2 programs be the same?

Answer:After 4 monthsStep-by-step explanation:The cost at both the programs consists of a "fixed cost" (reg fee)  & "variable cost" ( per month fee).Let number of months be "x"Yo-Yoga:35 fixed90 per monthSo equation would be: 35 + 90xEssence Yoga:75 fixed80 per monthSo equation would be: 75 + 80xTo find number of month when cost would be same, we equate both equations and solve for x:35 + 90x = 75 + 80x10x = 40x = 40/10x = 4hence, after 4 months, both cost would be same