Remember that quadratic formula:
![x= \frac{-b(+/-) \sqrt{b^{2}-4ac} }{2a}](https://tex.z-dn.net/?f=x%3D%20%5Cfrac%7B-b%28%2B%2F-%29%20%5Csqrt%7Bb%5E%7B2%7D-4ac%7D%20%7D%7B2a%7D%20)
is used to solve quadratic equations of the form
![ax^{2}+bx+c](https://tex.z-dn.net/?f=ax%5E%7B2%7D%2Bbx%2Bc)
.
Four our problem, the first one,
![(x-1)^2=4](https://tex.z-dn.net/?f=%28x-1%29%5E2%3D4)
, is not in the form
![ax^{2}+bx+c](https://tex.z-dn.net/?f=ax%5E%7B2%7D%2Bbx%2Bc)
. So is not a good idea to use the quadratic formula for this one.
The second one,
![0.25x^{2}+0.8x-8=0](https://tex.z-dn.net/?f=0.25x%5E%7B2%7D%2B0.8x-8%3D0)
, is in the correct form. Notice that in this equation
![a=0.25](https://tex.z-dn.net/?f=a%3D0.25)
,
![b=0.8](https://tex.z-dn.net/?f=b%3D0.8)
, and
![c=-8](https://tex.z-dn.net/?f=c%3D-8)
.
It would be appropriate to use the quadratic formula to solve this one.The third one,
![3x^{2}-4x=15](https://tex.z-dn.net/?f=3x%5E%7B2%7D-4x%3D15)
, can be expressed as:
![3x^{2}-4x-15=0](https://tex.z-dn.net/?f=3x%5E%7B2%7D-4x-15%3D0)
. This equation is also in the correct form. Here
![a=3](https://tex.z-dn.net/?f=a%3D3)
,
![b=-4](https://tex.z-dn.net/?f=b%3D-4)
, and
![c=-15](https://tex.z-dn.net/?f=c%3D-15)
.
It would be appropriate to use the quadratic formula to solve this one.The fourth one,
![(x-6)(x+6)=0](https://tex.z-dn.net/?f=%28x-6%29%28x%2B6%29%3D0)
, is not in the form
![ax^{2}+bx+c](https://tex.z-dn.net/?f=ax%5E%7B2%7D%2Bbx%2Bc)
. So is not a good idea to use the quadratic formula for this one.
We can conclude that you should use the quadratic formula to solve the
second and
third equations.
The mode of the dot plot is 20
Step-by-step explanation:
620 / 17 =36.47058.. ≈ 36.5
Answer: 6 boxes. average 45 each.
Step-by-step explanation:
You will use the idea of similar triangles to set up a ratio...
3/4=7/(4+PS) multiply both sides by 4
3=28/(4+PS) multiply both sides by 4+PS
12+3PS=28 subtract 12 from both sides
3PS=16 divide both sides by 3
PS=16/3
PS=5 1/3