Which expression has the same value as 8 + 2(3+x)?

Suppose a parabola has an axis of symmetry at x=-5, a maximum height of 9, and passes through the point (-7,1). Write the equati

Nutka1998 [239]

the parabola has maximum at 9, meaning is a vertical parabola and it opens downwards.

it has a symmetry at x = -5, namely its vertex's x-coordinate is -5.

check the picture below.

so then, we can pretty much tell its vertex is at (-5 , 9), and we also know it passes through (-7, 1)

$\bf ~~~~~~\textit{parabola vertex form} \\\\ \begin{array}{llll} y=a(x- h)^2+ k\qquad \leftarrow \textit{using this one}\\\\ x=a(y- k)^2+ h \end{array} \qquad\qquad vertex~~(\stackrel{}{ h},\stackrel{}{ k}) \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \begin{cases} h=-5\\ k=9 \end{cases}\implies y=a[x-(-5)]^2+9\implies y=a(x+5)^2+9$

$\bf \textit{we also know that } \begin{cases} x=-7\\ y=1 \end{cases}\implies 1=a(-7+5)^2+9 \\\\\\ -8=a(-2)^2\implies -8=4a\implies \cfrac{-8}{4}=a\implies -2=a \\\\[-0.35em] ~\dotfill\\\\ ~\hfill y=-2(x+5)^2+9~\hfill$

7 0

3 years ago

What does the quadratic function f(x)=x^2-10x+9 look like when it is rewritten in the form f(x) = a (x-h) + k

Tatiana [17]

ANSWER

When $f(x)=x^2-10x+9$ is written in the form $f(x)=a(x-h)^2+k$ , it looks like $f(x)=(x-5)^2-16$

EXPLANATION

To write $f(x)=x^2-10x+9$ in the form $f(x)=a(x-h)^2+k$ , we have to complete the squares.

We add and subtract half the coefficient of $x$ square.

$f(x)=x^2-10x+(-5)^2-(-5)^2+9$

The first three terms of the function is now a perfect square.

$f(x)=(x-5)^2-25+9$

We now simplify rto obtain,

$\Rightarrow f(x)=(x-5)^2-16$

6 0

4 years ago

Solve for the indicated variable. y = mx + b for x x=

kogti [31]

Answer:

y-b/m = x

Step-by-step explanation:

y = mx + b

~Subtract b to both sides

y - b = mx

~Divide m to both sides

y-b/m = x

Best of Luck!

3 0

4 years ago

I have a question on math homework, anybody have an answer? 11.5-3y=-48.5

tatyana61 [14]

Y=17.8 Please let me know if it is correct :)

5 0

3 years ago

Write an equation to represent the number of pages Jesse has read. Using x, the number of days Amir has been reading, write an e

katrin [286]

Question:

Jesse and Amir were assigned the same book to read. Jesse started reading on Saturday, and he is reading 30 pages a day. Amir didn't start until Sunday, but he is reading 35 pages a day.

How many days will it take Amir to catch up to Jesse, and how many pages will they each have read?

Write an equation to represent the number of pages Amir has read. Use x to represent the number of days Amir has been reading and y to represent the number of pages he has read.

Answer:

It will take 6 days

Step-by-step explanation:

For Jesse:

$Rate = 30\ pages/day$