18. Write down a formula for each situation: (a) A plumber has a fixed call-out charge of $80 and has an hourly rate of $60. Work out the total charge, C, for a job that takes L hours in which the cost of materials and parts is $K.
(b) An airport currency exchange booth charges a fixed fee of $10 on all transactions and offers an exchange rate of 1 dollar to 0.8 euros. Work out the total charge, C, (in $) for buying x euros.
(c) A firm provides 5 hours of in-house training for each of its semi-skilled workers and 10 hours of training for each of its skilled workers. Work out the total number of hours, H, if the firm employs a semi-skilled and b skilled workers.
(d) A car hire company charges $C a day together with an additional $c per mile. Work out the total charge, $X, for hiring a car for d days and travelling m miles during that time

the answer is 31.27mph

answer: b

step-by-step explanation: im sorry bro bro but thats not a eqation the human mind can answer and plus im a devil

15.36 per mile

but forgot to round

i am pretty sure

the answer would be d.

step-by-step explanation:

move all variables to the left side and all constants to the right side

(x−3)^2+(y−1)^2=16

this is the form of a circle. use this form to determine the center and radius of the circle.

( x − h ) 2 + ( y − k ) 2 = r 2

match the values in this circle to those of the standard form. the variable   r   represents the radius of the circle,   h   represents the x-offset from the origin, and   k   represents the y-offset from origin.

r = 4

h = 3

k = 1

the center of the circle is found at   ( h , k ) .

center:   ( 3 , 1 )

these values represent the important values for graphing and analyzing a circle.

center:   ( 3 , 1 ).

radius:   4