Answer:
Your solution is (9, 27) or x = 9, y = 27
Step-by-step explanation:
y = 2x + 9
y = 4x - 9
We can see that both of these equations equal y, so we can set them equal to each other.
2x + 9 = 4x - 9
Add 9 to both sides.
2x + 18 = 4x
Subtract 2x from both sides.
18 = 2x
Divide both sides by 2.
9 = x
Now we want to find y. To do this, plug x = 9 back into one of the original equations.
y = 2(9) + 9
Multiply.
y = 18 + 9
Add.
y = 27
Your solution is (9, 27)
Check your answer by plugging x = 9 and y = 27 back into the original equations.
y = 2x + 9
27 = 2(9) + 9
27 = 18 + 9
27 = 27
y = 4x - 9
27 = 4(9) - 9
27 = 36 - 9
27 = 27
Your answer is correct.
Hope this helps!
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:
Not a polygon
Step-by-step explanation:
[(3x+12)•(4x+4)]-(3x+8)-(4x)
[12x² + 12x + 48x + 48] - 3x - 8 - 4x
12x² + 60x + 48 - 7x - 8
12x² + 53x + 40
This is a degree 2 (quadratic) polynomial, not a polygon.
A polygon is an n-sided figure.
Example: A rectangle --> A four-sided polygon
Answer:
8 kilos of it is gold, since 2/5 in decimal form is 0.40
12 kilos of it is copper.
Step-by-step explanation:
Multiply 20 times 0.40, you get 8, so 8 kilos of it is gold, while 12 kilos is copper.
T^T
I'm pretty sure its c.........
