Answer:
A
Step-by-step explanation:
this is because a range is simply a collection of numbers that can be found in the domain
and since there is no domain, we assume that the numbers are all in the domain
leading us to our answer a
Let's set up two equations:
x+y=20 We know she brought total of 20, some of each so x=small y=big
20x+ 30y=450
x+y= 20
-y -y
------------
x= 20 -y
substitute into the other equation:
20 (20-y) + 30y = 450
400 - 20y + 30y = 450
400+ 10 y = 450
10 y = 50
y= 5
So she brought 5 big cases. Then substitute the value of y into one of the equations.
5+ x = 20
x= 15
So we bought 15 small cases and 5 big cases.
Hope this helps! Please give me the brainliest answer if you like it! If you have further questions, please leave a comment or add me as a friend!
Step-by-step explanation:
this is your answer..........
Answer:
0.51cm/s
Step-by-step explanation:
Area of a circle A = πr²
r is the radius
Rate of change of area is expressed as;
dA/dt = dA/dr • dr/dt
dA/dr = 2πr
radius r = 77cm
dA/dt = 79cm²
Get dr/dt
Substitute the given values into the formula
79 = 2π(77)•dr/dt
79 = 154dr/dt
dr/dt = 79/154
dr/dt = 0.51cm/s
Hence the rate of change of the radius is 0.51cm/s
