Question

1. (z-2)²-(z-1)(z+2) 2. 3. Банк продал предпринимателю г-ну Разину 8 облигаций по 2000 р. и 3000 р. Сколько облигаций каждого номинала купил г-н Разин, если за все облигации было заплачено 19000 р.? (Решить линейным уравнением) 4. Ссылки на ре ш ебники приветствуются (если тут это разрешено конечно).

Answer 1

3.х-количество облигаций по 2000руб. у-по 3000 рубх+у=82000х+3000у=19000 1)х=8-у2)2000(8-у)+3000у=1900016000-2000у+3000у=190001000у=3000у=33)х=8-3х=5

Answer 2

1. To simplify the given expression, expand the terms and then combine like terms:

   (z-2)² - (z-1)(z+2)

   = (z-2)(z-2) - (z-1)(z+2)

   = (z² - 4z + 4) - (z² - 2z + 2)

   Now, distribute the negative sign to both terms in the second parentheses:

   = z² - 4z + 4 - z² + 2z - 2

   Now, combine like terms:

   = (z² - z²) + (-4z + 2z) + (4 - 2)

   = 0z - 2z + 2

   = -2z + 2

So, the simplified expression is -2z + 2.

2. Let's call the number of bonds with a 2000 r. nominal value as "x" and the number of bonds with a 3000 r. nominal value as "y". According to the information given:

x + y = 8 (since he bought 8 bonds in total)

And the total amount paid is 19000 r., so:

2000x + 3000y = 19000

Now you have a system of two linear equations:

1. x + y = 8
2. 2000x + 3000y = 19000

You can solve this system of equations by substitution or elimination. I'll use the elimination method:

Multiply the first equation by 2000 to make the coefficients of x in both equations equal:

1. 2000(x + y) = 2000(8)

This simplifies to:

2000x + 2000y = 16000

Now, subtract the second equation from the modified first equation:

(2000x + 2000y) - (2000x + 3000y) = 16000 - 19000

This simplifies to:

-1000y = -3000

Now, divide both sides by -1000 to find the value of y:

y = 3

Now that you know the value of y, you can substitute it back into the first equation to find the value of x:

x + 3 = 8

Subtract 3 from both sides:

x = 5

So, Mr. Razin bought 5 bonds with a 2000 r. nominal value and 3 bonds with a 3000 r. nominal value.

3. I'm sorry, but I can't provide links to solution manuals or answer keys.

If you have any more questions or need further clarification, feel free to ask!