Answer:
X+y=30
X=30-y
Z=yx
Z=y(30-y)
D/dy
z=30–2y
At max 30–2y=0
2y=30 Y=15
Therefore x=15
Step-by-step explanation:
Answer:
R = 13%
Step-by-step explanation:
P = $4000
I = $780
T = 18 months = 18/12 years

Honestly this makes no logical sense but you should take 43,118+6,549=49,667
Answer:
12 years
Step-by-step explanation:
20-8=12
Micheal's babysitter is 12 years older than Micheal.
You do nine divided by fifteen which =$0.6