All categories

2 years ago

Solve z3+3z2−25z−75=0 .

1 answer:

3 0

z^3 + 3z^2 -25z - 75 = 0
Factor out common terms in the first two terms, then in the last two terms
z^2(z+3)−25(z+3)=0
Factor out the common term z+3
(z+3)(z^2−25)=0
Ask: When will (z+3)(z^2−25) equal zero?
When z+3=0 or z^2−25=0
Solve each of the 2 equations above
z=−3,±5

Hope this helps

You might be interested in

Pedro cut a sheet of poster board into 10 equal parts. His brother used some of the poster board and now 8/10 is left. Pedro wan

yawa3891 [41]

Answer: 8

Step-by-step explanation:

Given: Pedro cut a sheet of poster board into 10 equal parts.

let x be the total sheet.

then, one part of sheet= $\frac{1}{10}$ of the sheet

Now, His brother used some of the poster board and now 8/10 is left.

Therefore, if Pedro wants to make a sign from each remaining part of the poster board.

then, The number of signs he can make= $\frac{8}{10}\div \frac{1}{10}=\frac{8}{10}\times\frac{10}{1}=8$

Hence, Pedro can make 8 signs.

4 0

2 years ago

Read 2 more answers

Triangle A has a height of 2.5\text{ cm}2.5 cm2, point, 5, start text, space, c, m, end text and a base of 1.6\text{ cm}1.6 cm1,

konstantin123 [22]

Answer:

Option A

Option D

Option E

Step-by-step explanation:

we know that

If the height and base of triangle B are proportional to the height and base of triangle A

then

Triangle A and Triangle B are similar

Remember that

If two triangles are similar then the ratio of its corresponding sides is proportional and its corresponding angles are congruent

$\frac{h_A}{h_B} =\frac{b_A}{b_B}$

where

h_A and h_B are the height of triangle A and triangle B

b_A and b_B are the base of triangle A and triangle B

In his problem we have

$h_A=2.5\ cm\\b_A=1.6\ cm$

substitute

$\frac{2.5}{h_B} =\frac{1.6}{b_B}$

Rewrite

$\frac{2.5}{1.6} =\frac{h_B}{b_B}$

$\frac{h_B}{b_B}=1.5625$

Verify all the options

A) we have

$h_B=2.75\ cm\\b_B=1.76\ cm$

Find the ratio of the height to the base of triangle B and compare the result with the ratio of height to the base of triangle A (the value is 1.5625)

substitute the values in the proportion

$\frac{2.75}{1.76}=1.5625$

The ratios are the same

That means that are proportional

therefore

These values could be the height and base of triangle B

B) we have

$h_B=9.25\ cm\\b_B=9.16\ cm$

Find the ratio of the height to the base of triangle B and compare the result with the ratio of height to the base of triangle A (the value is 1.5625)

substitute the values in the proportion

$\frac{9.25}{9.16}=1.0098$

The ratios are not equal

That means that are not proportional

therefore

These values could not be the height and base of triangle B

C) we have

$h_B=3.2\ cm\\b_B=5\ cm$

Find the ratio of the height to the base of triangle B and compare the result with the ratio of height to the base of triangle A (the value is 1.5625)

substitute the values in the proportion

$\frac{3.2}{5}=0.64$

The ratios are not the same

That means that are not proportional

therefore

These values could not be the height and base of triangle B

D) we have

$h_B=1.25\ cm\\b_B=0.8\ cm$

Find the ratio of the height to the base of triangle B and compare the result with the ratio of height to the base of triangle A (the value is 1.5625)

substitute the values in the proportion

$\frac{1.25}{0.8}=1.5625$

The ratios are the same

That means that are proportional

therefore

These values could be the height and base of triangle B

E) we have

$h_B=2\ cm\\b_B=1.28\ cm$

Find the ratio of the height to the base of triangle B and compare the result with the ratio of height to the base of triangle A (the value is 1.5625)

substitute the values in the proportion

$\frac{2}{1.28}=1.5625$

The ratios are the same

That means that are proportional

therefore

These values could be the height and base of triangle B

8 0

2 years ago

Lin has 13 coins in her pocket that equal 40 cents. All the coins are dimes, d, and pennies, p. Which combination of coins does

Luden [163]

To answer this question you should begin with the coin that has a higher value. If you start with the dime and then just add the correct number of pennies to total $0.40, you will see that you will need 3 dimes ($0.30) and 10 pennies ($0.10).

I used a guess and check strategy starting with 2 dimes.

7 0

2 years ago

Read 2 more answers

Un tren pasa delante de un poste en 10 s y cruza un puente en 15 s. ¿En cuánto tiempo el tren cruzaría el puente si este tuviera

emmainna [20.7K]

Answer:

45 segundos.

Step-by-step explanation:

Un tren pasa por delante de un puente en 15 segundos; si el puente tuviera el doble de longitud, le tomaría el doble de tiempo en cruzarlo, si tuviera el triple de longitud, le tomaría el triple de tiempo y así sucesivamente.

En este caso, la pregunta es ¿En cuánto tiempo cruzaría el puente si tuviera el triple de su longitud? Por lo tanto, si cruza el puente en 15 segundos, teniendo el triple de longitud le tomaría 3 (15) = 45 segundos en cruzarlo.

6 0

2 years ago

A soccer coach is marking the lines for soccer field on a large recreation field. The dimensions of the field are to be 90 yards

mina [271]

Hello,

Diagonals of a rectangle must have the same measure.
You don't need to know the dimension of the diagonal but only if they are equals.

(√(90²+48²)=102 (yd))

5 0

2 years ago

Read 2 more answers