Set equal to 0
3=0, nope
3y-12=0
add 12
3y=12
divide 3
y=4
5p-4p-8=-2+3
p-8=1
p=9
1 solution
So, we'll say Mia gets $4.50 a day, since a standard weekend is two days, therefore adding up to $9 a weekend. So if Mia were to do her chores for 4 weekends, she'd have a total of $36 but not $40. So if she were to work an extra weekend, so 5 weekends, she'd have a total of $45. So you can say 5 weekends in order to earn more than $40.
Suppose:
C=cost
c=cost per kilo-watt hour
w=number of watts
h=number of hours
thus
C=kwhc
where:
k=constant of proportionality:
k=C/(whc)
but
C=15 when w=6000, h=10/60=1/6 hours, c=7.5 cents per kw/h
thus
k=15/(6000*1/6*7.5)
k=0.002
thus:
C=0.002(whc)
hence:
when
h=70*2=140=140/6=70/3 hours the cost will be:
C=0.002(6000*70/3*7.5)
C=2100 cents
C=$21
Answer:
I believe it might be C. -3
