the standard form of a quadratic formula is
y = ax^2 + bx + c
in this case you will solve using foil method
(× - 4)(x + 3)
<em>(</em><em>x</em><em> </em><em>×</em><em> </em><em>x</em><em>)</em><em> </em><em>+</em><em>(</em><em> </em><em>x</em><em> </em><em>×</em><em> </em><em>3</em><em> </em><em>)</em><em>(</em><em>-</em><em> </em><em>4</em><em> </em><em>×</em><em> </em><em>x</em><em>)</em><em> </em><em>(</em><em> </em><em>-4</em><em>)</em><em>×</em><em> </em><em>3</em><em>)</em><em>)</em>
<em>x</em><em>^</em><em>2</em><em> </em><em>+</em><em> </em><em>3x</em><em> </em><em>-</em><em> </em><em>4x</em><em> </em><em>-12</em>
<em>x</em><em>^</em><em>2</em><em> </em><em>-</em><em> </em><em>x</em><em> </em><em>-</em><em> </em><em>1</em><em>2</em>
<em>therefore</em><em> </em>
<em>y</em><em> </em><em>=</em><em> </em><em>x^</em><em>2-</em><em> </em><em>x</em><em> </em><em><u>-</u></em><em><u> </u></em><em><u>1</u></em><em><u>2</u></em><em><u> </u></em>
Check the picture below, so the parabola looks more or less like that.
now, the vertex is half-way between the focus point and the directrix, so that puts it where you see it in the picture, and the horizontal parabola is opening to the left-hand-side, meaning that the distance "P" is negative.
![\textit{horizontal parabola vertex form with focus point distance} \\\\ 4p(x- h)=(y- k)^2 \qquad \begin{cases} \stackrel{vertex}{(h,k)}\qquad \stackrel{focus~point}{(h+p,k)}\qquad \stackrel{directrix}{x=h-p}\\\\ p=\textit{distance from vertex to }\\ \qquad \textit{ focus or directrix}\\\\ \stackrel{"p"~is~negative}{op ens~\supset}\qquad \stackrel{"p"~is~positive}{op ens~\subset} \end{cases} \\\\[-0.35em] \rule{34em}{0.25pt}](https://tex.z-dn.net/?f=%5Ctextit%7Bhorizontal%20parabola%20vertex%20form%20with%20focus%20point%20distance%7D%20%5C%5C%5C%5C%204p%28x-%20h%29%3D%28y-%20k%29%5E2%20%5Cqquad%20%5Cbegin%7Bcases%7D%20%5Cstackrel%7Bvertex%7D%7B%28h%2Ck%29%7D%5Cqquad%20%5Cstackrel%7Bfocus~point%7D%7B%28h%2Bp%2Ck%29%7D%5Cqquad%20%5Cstackrel%7Bdirectrix%7D%7Bx%3Dh-p%7D%5C%5C%5C%5C%20p%3D%5Ctextit%7Bdistance%20from%20vertex%20to%20%7D%5C%5C%20%5Cqquad%20%5Ctextit%7B%20focus%20or%20directrix%7D%5C%5C%5C%5C%20%5Cstackrel%7B%22p%22~is~negative%7D%7Bop%20ens~%5Csupset%7D%5Cqquad%20%5Cstackrel%7B%22p%22~is~positive%7D%7Bop%20ens~%5Csubset%7D%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D)
![\begin{cases} h=-7\\ k=-2\\ p=-4 \end{cases}\implies 4(-4)[x-(-7)]~~ = ~~[y-(-2)]^2 \\\\\\ -16(x+7)=(y+2)^2\implies x+7=-\cfrac{(y+2)^2}{16}\implies x=-\cfrac{1}{16}(y+2)^2-7](https://tex.z-dn.net/?f=%5Cbegin%7Bcases%7D%20h%3D-7%5C%5C%20k%3D-2%5C%5C%20p%3D-4%20%5Cend%7Bcases%7D%5Cimplies%204%28-4%29%5Bx-%28-7%29%5D~~%20%3D%20~~%5By-%28-2%29%5D%5E2%20%5C%5C%5C%5C%5C%5C%20-16%28x%2B7%29%3D%28y%2B2%29%5E2%5Cimplies%20x%2B7%3D-%5Ccfrac%7B%28y%2B2%29%5E2%7D%7B16%7D%5Cimplies%20x%3D-%5Ccfrac%7B1%7D%7B16%7D%28y%2B2%29%5E2-7)
Answer:
Step-by-step explanation:
hello :
x² - 9x = 0
x(x-9)=0
x=0 or x-9=0
x=0 or x= 9
It is in the thousands place.
I think the answer is 1.125