Question

Maria and Sara combine their earnings to pay their bills. Maria’s earnings can be modeled by the equation A(x) = 12.85x + 53, where x is the number of hours worked in a week. Sara’s earnings are modeled by the equation B(x) = 7.55x + 143, where x is the number of hours worked in a week. What is the function that models their combined earnings.

Answer 1

A(x) = 12.85x + 53 where x is the number of hours that Maria worked in a week

B(x) = 7.55x + 143 where x is the number of hours that Sara worked in a week

we will change the "x" by "y" on the Sara's equation to make a difference with Maria's

So the equation for Sara would be:

B(y) = 7.55y + 143

If the add their earnings, that means we have to add A(x) and B(y)

Total earnings = A(x) + B(y) = (12.85x + 53) + (7.55y + 143)

Total earnings = 12.85x + 7.55y + 53 + 143

Total earnings = 12.85x + 7.55y + 196

So the answer is: 12.85x + 7.55y + 196

where x is the number of hours that Maria worked in a week

and y is the number of hours that Sara worked in a week