Answer: 1.25c
Step-by-step explanation:
The original cost of the DVDs is given as c.
The cost of the DVDs after a 25% markup is: c + 0.25c to show that 25% of c was being added to c to increase the price.
As both numbers in the equation have the same variable attached, they can be added. c is assumed to be 1c when it stands alone.
= c + 0.25c
= 1c + 0.25c
= 1.25c
