To find out if they are parallel we need to see if the gradient is the same, to do this we need to get y in terms of x:
assuming the first equation is x+y+7=0
y=-x-7
and
y=x-3
The gradient is the coefficient of x (the number infront of x)
For equation 1 the gradient is -1, and for number 2 it is 1, therefore they are not parallel.
However to check if they are perpendicular we need to see if their gradients multiply to equal -1.
-1*1=-1 therefore they are perpendicular
Step-by-step explanation:

Replace x and y.

Solve for y.

Square both sides.


This is the inverse function or you can also say

Answer:
Step-by-step explanation:
Ur answer should be C
Number of days Val rented the bicycle is 8
<h3><u>Solution:</u></h3>
Given that val paid a flat rental fee of $55.00 plus $8.50 each day
The total cost was $123
To find: number of days she rented the bicycle
Let "a" be the number of days she rented the bicycle
Rental fee = $55.00
Fee for one day = $ 8.50
So total cost is equal to rental fee and fee for "a" days
Total cost = rental fee + (number of days she rented the bicycle x Fee for one day)


123 - 55 = 8.50a
8.50a = 68

Thus number of days she rented the bicycle is 8