Answer:
C
Step-by-step explanation:
19^2 + x^2 = 21^2
19^2 = 361
21^2= 441
361 + x^2 = 441
x^2 = 441-361 = 80
x = sqrt(80) = 8.944 round to nearest tenth = 8.9
Answer:
18 minutes
Step-by-step explanation:
Given that:
The arrival time = 3 customers / hour
The avg. service rate (s) = 12 minutes per customer
To hour, we have:

s = 5 customers/ hour
Thus, the required average time for a customer needs to wait in line is:

To minutes;

= 18 minutes
Y=3x-10 and 3x+2y=16
y=3x-10
subsitute 3x-10 for y in other equation
3x+2y=16
3x+2(3x-10)=16
distribute
3x+6x-20=16
9x-20=16
add 20 both sides
9x=36
divide both sides by 9
x=4
sub back
y=3x-10
y=3(4)-10
y=12-10
y=2
x=4
y=2
(4,2) is soluiton