9. y=-1/4x^2+4x-19
group
y=(-1/4x^2+4x)-19
undistribute -1/4
y=-1/4(x^2-16x)-19
take 1/2 of -16 and squer it to get 64 then add neg and pos inside
y=-1/4(x^2-16x+64-64)-19
factorperfect square
y=-1/4((x-8)^2-64)-19
expand
y=-1/4(x-8)^2+16-19
y=-1/4(x-8)^2-3
vertex is (8,-3)
10.
group
y=(1/4x^2-3x)+18
undistribute
y=1/4(x^2-12x)+18
take 1/2 of -12 and square it and add neg and pos isndie
y=1/4(x^2-12x+36-36)+18
factor
y=1/4((x-6)^2-36)+18
expand
y=1/4(x-6)^2-9+18
y=1/4(x-6)^2+9
get to form (x-h)^2=4p(y-k)
minus 9 both sides and times 4
(x-6)^2=4(y-9)
(x-6)^2=4(1)(y-9)
so 1>0 so opens up and focus is 1 above vertex
vertex is (6,9)
so focus i (6,10)
11.
y=(-1/6x^2+7x)-80
y=(-1/6)(x^2-42x)-80
take 1/2 of linear coefient and squer it and add negative and positive inside
-42/2=-21, (-21)^2=441
y=(-1/6)(x^2-42+441-441)-80
factor perfect square the square
y=(-1/6)((x-21)^2-411)-80
expand
y=(-1/6)(x-21)^2+73.5-80
y=(-1/6)(x-21)^2-6.5
add 6.5 to both sid
y+6.5=(-1/6)(x-21)^2
times both sides by -6
-6(y+6.5)=(x-21)^2
(x-21)^2=-6(y+6.5)
(y-21)^2=4(-3/2)(y-(-6.5))
vertex is
-3/2<0 so directix is above
it is -3/2 or 1.5 units above the vertex
up is y so
-6.5+1.5=-5
the directix is y=-5
11.
in form (y-1)^2=4p(x+3)
opens left or right
(y-1)^2=4(4)(x+3)
vertex is (-3,1)
4>0 so opens right
dirextix is to left
it is 4 units to left
(-3,1)
left right is x
4 left of -3 is -4-3=7
x=-7 is da directix
Answer:
6 Chickens
Step-by-step explanation:
Let H represent the number of horses and C represent the number of chickens. Since there are 32 legs altogether this means that on equation to use would be given by:
2C + 4 H = 32 (Eq. 1)
Another equation can be made from the fact that there are 11 heads or 11 animals altogether which can be written as:
C + H = 11 (Eq. 2)
From Eq. 2, solve for the number of chickens:
C + H = 11
C = 11 - H (Eq. 3)
Substituting Eq. 3 in Eq. 1, the number of horses can be determined:
2 C + 4 H = 32
2 ( 11 − H ) + 4 H = 32
22 − 2 H + 4 H = 32
2H = 32 − 22
2 H = 10
H = 5 Eq.4
Putting Eq.4 in Eq.1
2C + 4*5 = 32
2C = 32 - 20
2C = 12
C = 12/2
C = 6
Answer:
A is correct, x=7, AB=20
Step-by-step explanation:
All of the options say x=7 so you can just input 7 into 4x-8 to find AB
4(7)-8=AB
28-8=AB
20=AB
Hope this helps, please mark brainliest :)
Unknown = x
the quotient of x and 12 is x/12 than 49 more than that is 53,
(x/12)+49=53, now use basic math and solve
-49 from both side,
x/12=4
*12 to both side,
x=48
therefore the unknown number is 48
The answer is 140°
Because we can use exterior angle property here
<u>Exter</u><u>ior</u><u> </u><u>angl</u><u>e</u><u> property</u><u> </u><u>:</u> It states that exterior angle is the sum of two opposite interior angles
y = 120 + 20 = 140°
