Start by calling the time spend on announcements 'A'. We can then set up an equation to represent the problem:

and then solve by multiplication to get:
A=0.6hours
We could also convert this into minutes:
Answer:
B
Step-by-step explanation:
600+12000+12000+35000=59600
^ if you're talking universally, no it would be cm. But no one really says "quarter inches". You would just say inches
X = <span>weight of the baby.
y = </span>weight of the doctor.
z = weight of the nurse.
x + y = 78 so y = 78 - x
x + z = 69 so z = 69 - x
x + y + z = 142
substitute y = 78 - x and z = 69 - x into x + y + z = 142
x + y + z = 142
x +78 - x + 69 - x = 142
-x + 147 = 142
-x = - 5
x = 5
answer
<span>the weight of the baby was 5 kg</span>
The distance between an arbitrary point on the surface and the origin is

Recall that for differentiable functions

and

, the composition

attains extrema at the same points that

does, so we can consider an augmented distance function

The Lagrangian would then be

We have partial derivatives

Set each partial derivative to 0 and solve the system to find the critical points.
From the second equation it follows that either

or

. In the first case we arrive at a contradiction (I'll leave establishing that to you). If

, then we have

This means

so that the points on the surface closest to the origin are

.