The answer is 1/6. To solve, simply set up an equation. It will be x/6. As you know, x can stand for anything. 1 will be the reasonable number for variable, x. Why? Well since x=1x. You don't actually write "1" Hope this makes your understanding clear.
The answer is B hope this helps
<h2>9.</h2><h3>Given</h3>
<h3>Find</h3>
- linear approximation to the volume when the radius increases 0.4 cm
<h3>Solution</h3>
The equation for volume of a sphere is
... V = (4/3)π·r³
Differentiating gives
... dV = 4π·r²·dr
Filling in the given numbers gives
... change in volume ≈ 4π·(15 cm)²·(0.4 cm)
... = 360π cm³ ≈ 1130.97 cm³ . . . . . . volume of layer 4mm thick
<h2>11.</h2><h3>Given</h3>
- an x by x by 2x cuboid with surface area 129.6 cm²
- rate of change of x is 0.01 cm/s
<h3>Find</h3>
<h3>Solution</h3>
The area is that of two cubes of dimension x joined together. The area of each such cube is 6x², but the two joined faces don't count in the external surface area. Thus the area of the cuboid is 10x².
The volume of the cuboid is that of two cubes joined, so is 2x³. Then the rate of change of volume is
... dV/dt = (d/dt)(2x³) = 6x²·dx/dt
We know x² = A/10, where A is the area of the cuboid, so the rate of change of volume is ...
... dV/dt = (6/10)A·dx/dt = 0.6·(129.6 cm²)(0.01 cm/s)
... dV/dt = 0.7776 cm³/s
<span>Simplifying
-15x2 + -2x + 8 = 0
Reorder the terms:
8 + -2x + -15x2 = 0
Solving
8 + -2x + -15x2 = 0
Solving for variable 'x'.
Factor a trinomial.
(2 + -3x)(4 + 5x) = 0
Subproblem 1Set the factor '(2 + -3x)' equal to zero and attempt to solve:
Simplifying
2 + -3x = 0
Solving
2 + -3x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-2' to each side of the equation.
2 + -2 + -3x = 0 + -2
Combine like terms: 2 + -2 = 0
0 + -3x = 0 + -2
-3x = 0 + -2
Combine like terms: 0 + -2 = -2
-3x = -2
Divide each side by '-3'.
x = 0.6666666667
Simplifying
x = 0.6666666667
Subproblem 2
Set the factor '(4 + 5x)' equal to zero and attempt to solve:
Simplifying
4 + 5x = 0
Solving
4 + 5x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-4' to each side of the equation.
4 + -4 + 5x = 0 + -4
Combine like terms: 4 + -4 = 0
0 + 5x = 0 + -4
5x = 0 + -4
Combine like terms: 0 + -4 = -4
5x = -4
Divide each side by '5'.
x = -0.8
Simplifying
x = -0.8
Solutionx = {0.6666666667, -0.8}</span>
