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4 years ago

Raspuns rapid !!!! Matematica clasa a 5a.

1 answer:

3 0

$U(1)=1\\U(1\times2)=2\\U(1\times2\times3)=6\\U(1\times2\times3\times4)=U(24)=4\\U(1\times\boxed{2}\times3\times4\times\boxed{5})=0 \text{ because of } 2\times5=10\\U(1\times\boxed{2}\times3\times4\times\boxed{5}\times6)=0 \text{ because of } 2\times5=10\\....................\\....................\\U(1\times\boxed{2}\times3\times4\times\boxed{5}\times6\times...\times2019)=0 \text{ because of } 2\times5=10$

$\implies~U(1+1\times2+1\times2\times3+1\times2\times3\times4+...+1\times2\times3\times....\times2019)=\\=U(1+1\times2+1\times2\times3+1\times2\times3\times4) = ~~~\text{(The others terms have U = 0)}\\=U(1+2+6+24)=U(33)=\boxed{\bf3}$

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What are the first three terms of the sequence: a1 = 3 and an = 2(an -1)^2?. . a. 2, 8, 18. . b. 3, 18, 648. . c. 3, 32, 50. . d

AlexFokin [52]

The first term of the sequence is already given to be 3. Use this value to obtain the second term.
a2 = 2(a1)^2 = 2(3)² = 18
Use the value of the second term to get the third term through the equation,
a3 = 2(a2)² = 2(18)² = 648
Thus, the answer to this item is letter B.

7 0

3 years ago

<img src="https://tex.z-dn.net/?f=%5Cleft%20%5C%7B%20%7B%7Bx%2By%3D1%7D%20%5Catop%20%7Bx-2y%3D4%7D%7D%20%5Cright.%20%5C%5C%5Clef

brilliants [131]

Answer:

(a) x=2, y=-1

(b) x=2, y=2

(c) $\displaystyle x=\frac{5}{2}, y=\frac{5}{4}$

(d) x=-2, y=-7

Step-by-step explanation:

Cramer's Rule

It's a predetermined sequence of steps to solve a system of equations. It's a preferred technique to be implemented in automatic digital solutions because it's easy to structure and generalize.

It uses the concept of determinants, as explained below. Suppose we have a 2x2 system of equations like:

$\displaystyle \left \{ {{ax+by=p} \atop {cx+dy=q}} \right.$

We call the determinant of the system

$\Delta=\begin{vmatrix}a &b \\c &d \end{vmatrix}$

We also define:

$\Delta_x=\begin{vmatrix}p &b \\q &d \end{vmatrix}$

And

$\Delta_y=\begin{vmatrix}a &p \\c &q \end{vmatrix}$

The solution for x and y is

$\displaystyle x=\frac{\Delta_x}{\Delta}$

$\displaystyle y=\frac{\Delta_y}{\Delta}$

(a) The system to solve is

$\displaystyle \left \{ {{x+y=1} \atop {x-2y=4}} \right.$

Calculating:

$\Delta=\begin{vmatrix}1 &1 \\1 &-2 \end{vmatrix}=-2-1=-3$

$\Delta_x=\begin{vmatrix}1 &1 \\4 &-2 \end{vmatrix}=-2-4=-6$

$\Delta_y=\begin{vmatrix}1 &1 \\1 &4 \end{vmatrix}=4-3=3$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-6}{-3}=2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{3}{-3}=-1$

The solution is x=2, y=-1

(b) The system to solve is

$\displaystyle \left \{ {{4x-y=6} \atop {x-y=0}} \right.$

Calculating:

$\Delta=\begin{vmatrix}4 &-1 \\1 &-1 \end{vmatrix}=-4+1=-3$

$\Delta_x=\begin{vmatrix}6 &-1 \\0 &-1 \end{vmatrix}=-6-0=-6$

$\Delta_y=\begin{vmatrix}4 &6 \\1 &0 \end{vmatrix}=0-6=-6$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-6}{-3}=2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{-6}{-3}=2$

The solution is x=2, y=2

$\displaystyle \left \{ {{-x+2y=0} \atop {x+2y=5}} \right.$

Calculating:

$\Delta=\begin{vmatrix}-1 &2 \\1 &2 \end{vmatrix}=-2-2=-4$

$\Delta_x=\begin{vmatrix}0 &2 \\5 &2 \end{vmatrix}=0-10=-10$

$\Delta_y=\begin{vmatrix}-1 &0 \\1 &5 \end{vmatrix}=-5-0=-5$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-10}{-4}=\frac{5}{2}$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{-5}{-4}=\frac{5}{4}$

The solution is

$\displaystyle x=\frac{5}{2}, y=\frac{5}{4}$

(d) The system to solve is

$\displaystyle \left \{ {{6x-y=-5} \atop {4x-2y=6}} \right.$

Calculating:

$\Delta=\begin{vmatrix}6 &-1 \\4 &-2 \end{vmatrix}=-12+4=-8$

$\Delta_x=\begin{vmatrix}-5 &-1 \\6 &-2 \end{vmatrix}=10+6=16$

$\Delta_y=\begin{vmatrix}6 &-5 \\4 &6 \end{vmatrix}=36+20=56$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{16}{-8}=-2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{56}{-8}=-7$

The solution is x=-2, y=-7

4 0

4 years ago

What does the slope of graph show about the Hardware stores selling price for the rope?

SashulF [63]

Answer:

If the price is increasing or decreasing

Step-by-step explanation:

The slope is a visual representation of the cost over time.

3 0

2 years ago

Read 2 more answers

Best Answer Gets Brainliest Please help asap

FrozenT [24]

<h2>Answer:</h2>

[1] Area of base = 13 × 13 = 169in².

Area of faces = 4 (1/2 × 13 × 8) = 208in².

Surface area = (169 + 208)in² = 377in².

[2] Area of base = 1/2 × 5.2 × 4.5 = 11.7in².

Area of faces = 3 (√3/4 × 5.2²) = 35.1in².

Surface area = (35.1 + 11.7)in² = 46.8in².

[3] Area of base = 7 × 10 = 70in².

Area of faces = 2(1/2 × 7 × 6) + 2(1/2 × 10 × 4.8)

= 98in².

Surface area = (70 + 98)in² = 168in².

7 0

3 years ago

A rectangular prism has dimensions of 3 cm. by 5 cm. by 5 cm. What is its surface area?

Bogdan [553]

$\bf \textit{surface area of a rectangular prism}\\\\ SA=2Lw+2Lh+ 2wh~~ \begin{cases} L=length\\ w=width\\ h=height\\ \cline{1-1} L=3\\ w=5\\ h = 5 \end{cases} \\\\\\ SA=2(3\cdot 5)+2(3\cdot 5)+2(5\cdot 5)\implies SA=30+30+50\implies SA=110$

4 0

3 years ago