Which relationships have the same constant of proportionality between yyy and xxx as the following table? xxx yyy 444 323232 777 565656 888 646464 Choose 3 answers: Choose 3 answers:
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The equation after completing the square is (z + 4)² = 80
The solutions to the given equation in the simplest radical form are z = -4 + 4√5 and z = -4 - 4√5
<h3>Completing the square </h3>
From the question, we are to solve the given quadratic equation by completing the square
The given equation is
z² +8z - 44 =20
First, add 44 to both sides of the equation
z² +8z - 44 + 44 = 20 + 44
z² +8z = 64
Now, divide the coefficient of z by 2, square the value and add to both sides
The coefficient of z is 8
Dividing
8/2 = 4
Squaring
4²
Now, add this to both sides
That is,
z² +8z +4² = 64 + 4²
(z + 4)² = 64 + 16
(z + 4)² = 80
The equation after completing the square is
(z + 4)² = 80
Continuation
(z + 4)² = 80
Take the square root of both sides
√(z + 4)² = ±√80
z + 4 = ±√80
z = -4 ± √80
z = -4 ± 4√5
z = -4 + 4√5 and z = -4 - 4√5
Hence,
The equation after completing the square is (z + 4)² = 80
The solutions to the given equation in the simplest radical form are z = -4 + 4√5 and z = -4 - 4√5
Learn more on Completing the square here: brainly.com/question/49444
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<h3>Given</h3>
- length, width, and height of a cuboid are x, x, and 2x, respectively
- the cuboid's surface area is 129.6 cm²
- dx/dt = 0.01 cm/s
<h3>Find</h3>
- dV/dt for the given conditions
<h3>Solution</h3>
The equation for surface area can be written
... A = 2(LW +H(L +W))
Substituting the given values gives an equation that we can solve for x
... 129.6 = 2(x·x +2x(x +x)) = 10x²
... x = √(129.6/10) = 3.6 . . . . . . . cm
The equation for volume can be written
... V = LWH
Substituting the given values gives an expression for volume in terms of x.
... V = x·x·2x = 2x³
Then the rate of change of volume is
... dV/dt = 6x²·dx/dt
... dV/dt = 6·(3.6 cm)²·(0.01 cm/s)
... dV/dt = 0.7776 cm³/s
1 litre= 1000mL
Given: 2 liters
2×1000= 2000 litre
Now to find %
250/2000 × 100
Answer: 12.5%
