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3 years ago

Solve for x in the equation x^2+4x-4 = 8.

Mathematics

1 answer:

ollegr [7]3 years ago

8 0

Answer:

Its the first choice.

Step-by-step explanation:

x^2+4x-4 = 8

x^2 + 4x - 4 - 8 = 0

x^2 + 4x - 12 = 0

(x + 6)(x - 2) = 0

x = -6, 2.

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A girls' choir is choosing a concert uniform. They can pick red, green, or purple sweaters, and they can pick tan or black skirt

Fynjy0 [20]

<h3>Answer: C) 12</h3>

======================================================

Explanation:

There are 3 colors of sweaters {red, green, purple} and 2 colors of skirts {tan, black}

So far there are 3*2 = 6 different outfit combinations. Imagine a table with 3 rows representing the sweater colors and 2 columns representing the skirt colors. There would be 6 cells in the table representing each possible combination. One cell would have (red sweater, tan skirt) for instance.

For each of those 6 combinations, we also have 2 shoe colors. So overall we have 6*2 = 12 outfit combinations

The tree diagram is shown below. Note how there are 3*2*2 = 12 different paths to follow.

7 0

3 years ago

What sum is represented by the following number line?

Mama L [17]

Answer:

Step-by-step explanation:

3 0

3 years ago

Use Lagrange multipliers to find the maximum and minimum values of the function subject to the given constraint. (If an answer d

andrey2020 [161]

Answer:

The maximum value is 1/27 and the minimum value is 0.

Step-by-step explanation:

Note that the given function is equal to $(xyz)^2$ then it means that it is positive i.e $f(x,y,z)\geq 0$ .

Consider the function $F(x,y,z,\lambda)=x^2y^2z^2-\lambda (x^2+y^2+z^2-1)$

We want that the gradient of this function is equal to zero. That is (the calculations in between are omitted)

$\frac{\partial F}{\partial x} = 2x(y^2z^2 - \lambda)=0$

$\frac{\partial F}{\partial y} = 2y(x^2z^2 - \lambda)=0$

$\frac{\partial F}{\partial z} = 2z(x^2y^2 - \lambda)=0$

$\frac{\partial F}{\partial \lambda} = (x^2+y^2+z^2-1)=0$

Note that the last equation is our restriction. The restriction guarantees us that at least one of the variables is non-zero. We've got 3 options, either 1, 2 or none of them are zero.

If any of them is zero, we have that the value of the original function is 0. We just need to check that there exists a value for lambda.

Suppose that x is zero. Then, from the second and third equation we have that

$-2y\lambda = -2z\lambda$ . If lambda is not zero, then y =z. But, since $-2y\lambda=0$ and lambda is not zero, this implies that x=y=z=0 which is not possible. This proofs that if one of the variables is 0, then lambda is zero. So, having one or two variables equal to zero are feasible solutions for the problem.

Suppose that only x is zero, then we have the solution set $y^2+z^2=1$ .

If both x,y are zero, then we have the solution set $z^2=1$ . We can find the different solution sets by choosing the variables that are set to zero.

NOw, suppose that none of the variables are zero.

From the first and second equation we have that

$\lambda = y^2z^2 = x^2z^2$ which implies $x^2=y^2$

Also, from the first and third equation we have that

$\lambda = y^2z^2 = x^2y^2$ which implies $x^2=z^2$

So, in this case, replacing this in the restriction we have $3z^2=1$ , which gives as another solution set. On this set, we have $x^2=y^2=z^2=\frac{1}{3}$ . Over this solution set, we have that the value of our function is $\frac{1}{3^3}= \frac{1}{27}$

4 0

3 years ago

(7 + X) x 8 - 4 x X = 56

devlian [24]

Answer:

12 1/4

Step-by-step explanation:

(7 + X) × 8 - 4 × X = 56

7 + X × 8 - 4 × X = 56

7 + 8X - 4 × X = 56

7 + 8X - 4X = 56

7 + 4X = 56

4X = 56 - 7

X = 49/4

X = 12 1/4

7 0

2 years ago

Find the two square roots of 144.

spin [16.1K]

Answer:

The square root function

sqrt(144) or √144 produces a single positive value, 12.

However if you have an equation

x² = 144, then you have two possible values for x, 12 and -12.

Two ways to look at it.

x² - 144 = 0

Difference of two squares

(x+12)(x-12) = 0

x = -12, 12

x² = 144

x = ±√144

x = ±12

x = -12, 12

4 0

3 years ago

Read 2 more answers