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3 years ago

Ans

Mathematics

1 answer:

castortr0y [4]3 years ago

8 0

The correct answer is $4.22.

Is states that Brian purchased 4 items that were $1.00.

That means he has spent a total of $4.00.

5.5% of $4.00 is 0.22.

Add that together and it gives you the sum/answer of $4.22.

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Negative two and one-fourth divded by negative one and one-half

Bond [772]

Answer:

The answer is 3/2 or 1 1/2

Step-by-step explanation:

First, you have to make it as a improper fraction :

$- 2 \frac{1}{4}$

$= - \frac{( 2 \times 4) + 1}{4}$

$= - \frac{9}{4}$

$- 1 \frac{1}{2}$

$= - \frac{(1 \times 2) + 1}{2}$

$= - \frac{3}{2}$

Next, you can divide it by cutting out the common factor :

$- \frac{9}{4} \div - \frac{3}{2}$

$= - \frac{9}{4} \times - \frac{2}{3}$

$= - \frac{ 3}{2} \times - 1$

$= \frac{3}{2}$

$= 1 \frac{1}{2}$

3 0

3 years ago

Find the greatest solution for x+y when x^2+y^2 = 7, x^3+y^3=10

damaskus [11]

Answer:

Step-by-step explanation:

set

$f(x,y)=x+y\\$

constrain:

$g(x,y)=x^2+y^2 = 7\\h(x,y)=x^3+y^3=10$

Partial derivatives:

$f_{x}=1\\f_{y} =1 \\g_{x}=2x \\g_{y}=2y\\h_{x}=3x^2 \\h_{y}=3y^2$

Lagrange multiplier:

$grad(f)=a*grad(g)+b*grad(h)\\$

$\left[\begin{array}{ccc}1\\1\end{array}\right]=a\left[\begin{array}{ccc}2x\\2y\end{array}\right]+b\left[\begin{array}{ccc}3x^2\\3y^2\end{array}\right]$

4 equations:

$1=2ax+3bx^2\\1=2ay+3by^2\\x^2+y^2=7\\x^3+y^3=10$

By solving:

$a=4/9\\b=-2/27\\x+y=4$

Second mathod:

Solve for x^2+y^2 = 7, x^3+y^3=10 first:

$x=\frac{1}{2} -\frac{\sqrt{13}}{2} \ or \ y=\frac{1}{2} +\frac{\sqrt{13}}{2} \\x=\frac{1}{2} +\frac{\sqrt{13}}{2} \ or \ y=\frac{1}{2} -\frac{\sqrt{13}}{2} \\x+y=-5\ or\ 1 \or\ 4$