5x^2+4x-2 This is a second degree polynomial since the largest exponent is x^2
![B^2=256](https://tex.z-dn.net/?f=B%5E2%3D256)
![\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}](https://tex.z-dn.net/?f=%5Cmathrm%7BFor%5C%3A%7Dx%5E2%3Df%5Cleft%28a%5Cright%29%5Cmathrm%7B%5C%3Athe%5C%3Asolutions%5C%3Aare%5C%3A%7Dx%3D%5Csqrt%7Bf%5Cleft%28a%5Cright%29%7D%2C%5C%3A%5C%3A-%5Csqrt%7Bf%5Cleft%28a%5Cright%29%7D)
![B=\sqrt{256},\:B=-\sqrt{256}](https://tex.z-dn.net/?f=B%3D%5Csqrt%7B256%7D%2C%5C%3AB%3D-%5Csqrt%7B256%7D)
![\sqrt{256}](https://tex.z-dn.net/?f=%5Csqrt%7B256%7D)
![\mathrm{Factor\:the\:number:\:}\:256=16^2](https://tex.z-dn.net/?f=%5Cmathrm%7BFactor%5C%3Athe%5C%3Anumber%3A%5C%3A%7D%5C%3A256%3D16%5E2)
![=\sqrt{16^2}](https://tex.z-dn.net/?f=%3D%5Csqrt%7B16%5E2%7D)
![=16](https://tex.z-dn.net/?f=%3D16)
![-\sqrt{256} =-16](https://tex.z-dn.net/?f=-%5Csqrt%7B256%7D%20%3D-16)
![B=16,\:B=-16](https://tex.z-dn.net/?f=B%3D16%2C%5C%3AB%3D-16)
<h3><em>
Hope I helped you!</em></h3><h3><em>
Success!</em></h3>
<em>by a random romanian guy</em>
Answer:
what's the question ndndn
8 Is your answer so option A
The cosine of angle X is
![\cos X=\dfrac{XY}{XZ}=\dfrac{XY}{7.5}](https://tex.z-dn.net/?f=%5Ccos%20X%3D%5Cdfrac%7BXY%7D%7BXZ%7D%3D%5Cdfrac%7BXY%7D%7B7.5%7D)
By the Pythagorean theorem, we have
![XY^2+YZ^2=XZ^2\implies XY=\sqrt{7.5^2-6^2}=4.5](https://tex.z-dn.net/?f=XY%5E2%2BYZ%5E2%3DXZ%5E2%5Cimplies%20XY%3D%5Csqrt%7B7.5%5E2-6%5E2%7D%3D4.5)
Then
![\cos X=\dfrac{XY}{XZ}=\dfrac{4.5}{7.5}](https://tex.z-dn.net/?f=%5Ccos%20X%3D%5Cdfrac%7BXY%7D%7BXZ%7D%3D%5Cdfrac%7B4.5%7D%7B7.5%7D)
Multiplying numerator and denominator by 2, we get
.