<h2>
Explanation:</h2>
In physics, work is defined force that causes displacement. So this can be expressed by the following equation:

Where:

The force can be found as:

And for the displacement:

The force (weight) is down and the displacement is up, then the work must be negative. So:

Answer:
C
Step-by-step explanation:
The same x value cannot be used more than once or it isn't a function.
Answer:
520
Step-by-step explanation:
This problem is
boys + girls = total
Boys = 442
Girls = 15% of the total
Therefore, substituting in, gives us:
442 + .15t = t, where t is total
Then 442 = .85t and
t = 520
Answer:
45.82 square inches
Step-by-step explanation:
Use the formula for the surface area of a sphere, A = 4
r²
If the diameter is 3.82 inches, the radius is 1.91 inches.
Plug in 3.14 as
and 1.91 as r, and solve:
A = 4
r²
A = 4(3.14)(1.91²)
A = 45.82
So, approximately 45.82 square inches of material are needed.
F(x) = x² + x - 20 = x² + 5x - 4x - 20 = x(x + 5) - 4(x + 5) = (x + 5)(x - 4)
f(x) = 0 ⇔ (x + 5)(x - 4) = 0 ⇔ x + 5 = 0 or x - 4 = 0 ⇒ x = -5 or x = 4
Answer: C. x = -5 and x = 4.