What would be the new function ?

y = 90x + 50

Step-by-step explanation:

Before, the function was y = 85x + 50, and the $85 for each our of a $50 house call. If the rate for each hour turns into 90, as in $90, then the function will take the 90 in to replace the 85: y = 90x + 50.

Hope this helped.

45

step-by-step explanation:

to find a percentage, add a decimal in front and multiply it by the other number.

.25 times 180= 45