Karma was given some birthday money. She puts the money in an account. Every month after that, she deposits the same amount of money.

The equation that models this situation is [tex]y = 75x + 60[/tex], where [tex]y[/tex] is the amount of money in the account and [tex]x[/tex] is the number of deposits.

What does the [tex]y[/tex]-intercept mean in this situation?

A. She was given [tex]\[tex]$75[/tex] for her birthday.
B. She puts [tex]\$[/tex]60[/tex] in the account each month.
C. She puts [tex]\[tex]$75[/tex] in the account each month.
D. She was given [tex]\$[/tex]60[/tex] for her birthday.



Answer :

To determine the meaning of the [tex]\( y \)[/tex]-intercept in the equation [tex]\( y = 75x + 60 \)[/tex], let's break down the components of the equation:

1. [tex]\( y \)[/tex] represents the total amount of money in the account after [tex]\( x \)[/tex] months.
2. [tex]\( x \)[/tex] is the number of months (or number of deposits made).
3. The coefficient [tex]\( 75 \)[/tex] indicates how much money Karma deposits each month.
4. The [tex]\( y \)[/tex]-intercept is the constant term [tex]\( 60 \)[/tex] in the equation.

The [tex]\( y \)[/tex]-intercept of an equation is the value of [tex]\( y \)[/tex] when [tex]\( x = 0 \)[/tex]. This represents the initial amount of money in the account before any deposits are made.

Therefore, when [tex]\( x = 0 \)[/tex]:
[tex]\[ y = 75(0) + 60 = 60. \][/tex]

So, when no deposits have been made yet (i.e., [tex]\( x = 0 \)[/tex]), the amount of money in the account is [tex]$60. This $[/tex]60 is the initial amount she had in the account, which is the birthday money she was given.

Thus, the [tex]\( y \)[/tex]-intercept corresponds to the initial amount of money she had in the account before making any deposits.

The correct interpretation of the [tex]\( y \)[/tex]-intercept in this context is:
D. She was given [tex]$\$[/tex] 60$ for her birthday.