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3 years ago

Please help me with some Algebra 2!

Mathematics

1 answer:

enot [183]3 years ago

6 0

Answer:

12750

Step-by-step explanation:

The sequence of visitors is

50, 100, 200, 400, .....

This is a geometric sequence

with common ratio r = 2

The sum to n terms is found using

$S_{n}$ = $\frac{a(r^n-1)}{r-1}$ ( a is the first term )

$S_{8}$ = $\frac{50(2^8-1}{2-1}$ = 50 × 255 = 12750

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A loan worth $1000 collects simple interest each year for 6 years. At the end of that time, a total of $1270 is paid back. Deter

Korolek [52]

Answer:

The percentage rate is 4.5%

Step-by-step explanation:

The simple interest earned in this situation is $1270 - $1000, or $270.

the simple interest formula is i =prt.

Here, i = $270 = ($1000)(r)(6 yr).

$270

Then r = ------------------- = 0.045

$1000(6 yr)

The percentage rate is 4.5%

5 0

2 years ago

enelope determined the solutions of the quadratic function by completing the square. f(x) = 4x2 + 8x + 1 –1 = 4x2 + 8x –1 = 4(x2

Marat540 [252]

The correct question is
<span>Penelope determined the solutions of the quadratic function by completing the square.
f(x) = 4x² + 8x + 1
–1 = 4x² + 8x
–1 = 4(x² + 2x)
–1 + 1 = 4(x² + 2x + 1)
0 = 4(x + 2)²
0 = (x + 2)²
0 = x + 2
–2 = x
What error did Penelope make in her work?

we have that
</span>f(x) = 4x² + 8x + 1
to find the solutions of the quadratic function
let
f(x)=0
4x² + 8x + 1=0

Group terms that contain the same variable, and move the constant to the opposite side of the equation

(4x² + 8x)=-1

Factor the leading coefficient

4*(x² + 2x)=-1

Complete the square Remember to balance the equation by adding the same constants to each side.

4*(x² + 2x+1)=-1+4 --------> ( added 4 to both sides)

Rewrite as perfect squares

4*(x+1)²=3

(x+1)²=3/4--------> (+/-)[x+1]=√3/2

(+)[x+1]=√3/2---> x1=(√3/2)-1----> x1=(√3-2)/2

(-)[x+1]=√3/2----> x2=(-2-√3)/2

therefore

the answer is

<span>Penelope should have added 4 to both sides instead of adding 1.</span>

6 0

3 years ago

Read 2 more answers

Write 3x^2-18x-6 in vertex form

Vedmedyk [2.9K]

The standard form of a quadratic equation is $\displaystyle{ y=ax^2+bx+c$ , while the vertex form is:

$y=a(x-h)^2+k$ , where (h, k) is the vertex of the parabola.

What we want is to write $\displaystyle{ y=3x^2-18x-6$ as $y=a(x-h)^2+k$

First, we note that all the three terms have a factor of 3, so we factorize it and write:

$\displaystyle{ y=3(x^2-6x-2)$ .

Second, we notice that $x^2-6x$ are the terms produced by $(x-3)^2=x^2-6x+9$ , without the 9. So we can write:

$x^2-6x=(x-3)^2-9$ , and substituting in $\displaystyle{ y=3(x^2-6x-2)$ we have:

$\displaystyle{ y=3(x^2-6x-2)=3[(x-3)^2-9-2]=3[(x-3)^2-11]$ .

Finally, distributing 3 over the two terms in the brackets we have:

$y=3[x-3]^2-33$ .

Answer: $y=3(x-3)^2-33$