So whats the question or you stating a statement.
Perpendicular is slope multiplies to -1
for
ax+by=c
slope=-a/b
4x-3y=6
-a/b=-4/-3=4/3
perpendicular to 4/3 is -3/4
point slope form
y-y1=m(x-x1)
for slope=m
a point is (x1,y1)
point (4,-2)
slope is -3/4
y-(-2)=-3/4(x-4)
y+2=-3/4(x-4)
or converted
y=-3/4x+1
or
3x+4y=4
Answer:
The number of service calls made = 55
Step-by-step explanation:
Let the total number of installations made by the company = x
Let the total number of service calls = y
Total number of invoices for the month = 69
=>
-------------------(1)
Total amount of the invoices = $6975
=>
-----------(2)
From (1), ![\[y=69-x\]](https://tex.z-dn.net/?f=%5C%5By%3D69-x%5C%5D)
Substituting in (2):
=> ![\[400x+25*(69-x)=6975\]](https://tex.z-dn.net/?f=%5C%5B400x%2B25%2A%2869-x%29%3D6975%5C%5D)
=> ![\[400x+1725-25x=6975\]](https://tex.z-dn.net/?f=%5C%5B400x%2B1725-25x%3D6975%5C%5D)
=> ![\[375x=5250\]](https://tex.z-dn.net/?f=%5C%5B375x%3D5250%5C%5D)
=> ![\[x=14\]](https://tex.z-dn.net/?f=%5C%5Bx%3D14%5C%5D)
![\[y=69-x\]](https://tex.z-dn.net/?f=%5C%5By%3D69-x%5C%5D)
=> ![\[y=55\]](https://tex.z-dn.net/?f=%5C%5By%3D55%5C%5D)