Write an equation for each situation using the two given variables.(a) Gwen received a gift card for $400. She uses it each month to treat herself to a mani-pedi for $35. Let D be the money on her gift card after m months.

Answer 1

Initially, she had $400

Every month, this amount decreases by the amount she spends, which is $35

So, the amount she has used after 'm' months is: 35 * m

The amount left after 'm' months
= Initial - Money used
= 400 - 35*m

So,

D = 400 - 35m