All categories

3 years ago

Which expression is equal to −2i(4−i)?

Mathematics

2 answers:

Cloud [144]3 years ago

6 0

The answer is A -2-8i

Anni [7]3 years ago

4 0

Answer:

The correct option is A.

Step-by-step explanation:

The given expression is

$-2i(4-i)$

We need to find the simplified form of the given expression.

Using distributive property we get

$-2i(4)-2i(-i)$

$-8i+2i^2$

We know that $i^2=-1$ . Using this fact we get

$-8i+2(-1)$

$-8i-2$

Write the above expression as a+ib.

$-2-8i$

Therefore the correct option is A.

You might be interested in

Explain the difference between -<img src="https://tex.z-dn.net/?f=%5Csqrt%7B1%7D" id="TexFormula1" title="\sqrt{1}" alt="\sqrt{1

OLEGan [10]

Step-by-step explanation:

= -√1

= -1

= √1

= 1

Difference -√1 and √1 are the sign of the number, where -√1 is negative and √1 is positive

3 0

3 years ago

What is the average rate of change of f over the interval -7 < or equal to x Give an exact number

Annette [7]

Answer:

$\frac{4}{3}$

Step-by-step explanation:

The average rate of change can be found by using the following formula

$\frac{f(x_{2}) - f(x_{1}) }{x_{2} - x_{1}}$

Since the interval goes from -7 to 2, we should find the y-values that correspond to x=-7 and x=2.

By inspection of the graph, we can clearly see that when x is -7, y is -7 as well and when x is 2, y is 5.

Now that we know this, we can simply plug these values into the formula!

$\frac{f(2) - f(-7) }{2 - (-7)} = \frac{5 - (-7)}{2 - (-7)} = \frac{5 +7}{2+7} = \frac{12}{9} = \frac{4}{3}$

Good luck!

3 0

2 years ago

All regular polygons:

Andrews [41]

Answer:

all regular polygons are symmetrical!!

hope this helped!

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Round 7.954 to the place named

Andrej [43]

What is it rounded too?

4 0

3 years ago

What is the most precise classification of the quadrilateral formed by connecting in order the midpoints of the figure below? Sh

AlekseyPX

Answer:

Rhombus

Step-by-step explanation:

The given trapezoid has vertices at M(-4,0), J(-2,4), K(2,4), and L(4,0).

Use the midpoint formula: $(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2})$

To obtain the midpoint of MJ:

$A=(\frac{-4+-2}{2},\frac{0+4}{2})=(-3,2)$

Similarly, the midpoint of of JK is B=(0,4), the midpoint of KL is C=(3,2), and the midpoint of LM is D=(0,0).

Now use the slope formula;

$m=\frac{y_2-y_1}{x_2-x_1}$

To find the slope of AB = $\frac{4-2}{0--3}=\frac{2}{3}$

The slope of BC = $\frac{2-4}{3-0} =-\frac{2}{3}$

The slope of CD= $\frac{0-2}{0-3}=\frac{2}{3}$

The slope of AD= $\frac{0-2}{0--3}=-\frac{2}{3}$

We can see that the slope of the opposites sides are parallel, CD is parallel to AB and AD is parallel to BC.

The product of the slopes of the adjacent sides is not -1.

Hence the shape formed by connecting the midpoint of the isosceles trapezoid is a parallelogram.

Obviously the side lengths are equal since we connected all midpoints.

The parallelogram is a rhombus.

7 0

3 years ago