Question

Wanda has $640 in her checking account. She pays her landlord $75 per week for rent.

Which function best models the linear relationship?

y = 640x + 75
y = −75x + 640
y = −75x - 640
y = 75x + 640

Answer 1

y = 75×-640 that is the answer

Answer 2

If Wanda has 640 in her checking account and she pays her landlord $75 per week for rent, the function best models the linear relationship is y=-75x+640.

Explanation:

Wanda has 640 in her checking account, that’s money that she already has, so it’s a positive value: 640.

The “x” represents the number of weeks that she will pay, each week have a price of 75, so we will multiply it for x, knowing that it is a payment that will be deducted from her money, we assume it is a negative value: -75x

The function is y= 640 – 75x, taking into account the commutative property of addition*, this function is the same that y= -75x + 640

*commutive property of addition: the order of two numbers that will be added can be changed without affecting the sum.