Answer:
1
2
− 1
9
8
Step-by-step explanation:
Answer: 
Step-by-step explanation:
Given
New mail carrier takes 4 hours for delivery i.e.
New mail carrier completes
part of work in 1 hour
Old mail carrier takes 3 hours for delivery i.e.
mail carrier completes
part of work in 1 hour
If they work together, they complete the work in x hours i.e.

Answer:
There are no extraneous solutions
Reasoning:
An extraneous solution is a solution that isn't valid, it might be imaginary like the square root of a negative number.
first we want to isolate z:
1+sqrt(z)=sqrt(z+5)
^2 all ^2 all
(1+sqrt(z))(1+sqrt(z))=z+5
expand
1+2sqrt(z)+z=z+5
-1 -z -z -1
2sqrt(z)=4
/2 /2
sqrt(z)=2
^2 all ^2 all
z=4
Since there is one solution and it is a real number, there are no extraneous solutions.
Density = Mass/Volume
Density = 6/12 = 0.5 g/mL or 0.5 kg/L
Answer:
$690.86
Step-by-step explanation:
100% from the original cost is: 2 x 863.57 = $1,727.14
40/100 = X/1727.14 (40 percent is what of 1,727.40) (%/100 = is/of)
(40 * 1,727.14) / 100 = $ 690.86