Answer:
c
Step-by-step explanation:
the answer is c becuase i know this que
Plug 8 into the equation for y and you get 2+24 or 26.
Answer:
Step-by-step explanation:
Answer:
![x(x-1)(x+3)](https://tex.z-dn.net/?f=x%28x-1%29%28x%2B3%29)
Step-by-step explanation:
Factor out the common terms, and get: ![x(x^2+2x-3)](https://tex.z-dn.net/?f=x%28x%5E2%2B2x-3%29)
Factor
, and get: ![(x-1)(x+3)](https://tex.z-dn.net/?f=%28x-1%29%28x%2B3%29)
<em>Hope this helps!!</em>
Answer:
3. C
4. D
Step-by-step explanation:
3.
![x^2+25=0\\x^2=-25\\x=\pm\sqrt{-25}](https://tex.z-dn.net/?f=x%5E2%2B25%3D0%5C%5Cx%5E2%3D-25%5C%5Cx%3D%5Cpm%5Csqrt%7B-25%7D)
Once ![\sqrt{-1}=i](https://tex.z-dn.net/?f=%5Csqrt%7B-1%7D%3Di)
![x=\pm5i](https://tex.z-dn.net/?f=x%3D%5Cpm5i)
4.
A quadratic equation has no real roots when the discriminant (
) is negative.
.
Let's try all the equations:
(A)
![2x^2-7x-9=0\\\\\Delta=\sqrt{\left(-7\right)^2-4\cdot \:2\left(-9\right)}\\\Delta=\sqrt{\left(-7\right)^2+4\cdot \:2\cdot \:9}\\\Delta=\sqrt{121} \\\Delta=11](https://tex.z-dn.net/?f=2x%5E2-7x-9%3D0%5C%5C%5C%5C%5CDelta%3D%5Csqrt%7B%5Cleft%28-7%5Cright%29%5E2-4%5Ccdot%20%5C%3A2%5Cleft%28-9%5Cright%29%7D%5C%5C%5CDelta%3D%5Csqrt%7B%5Cleft%28-7%5Cright%29%5E2%2B4%5Ccdot%20%5C%3A2%5Ccdot%20%5C%3A9%7D%5C%5C%5CDelta%3D%5Csqrt%7B121%7D%20%5C%5C%5CDelta%3D11)
(B)
![2x^2=7x\\2x^2-7x=0\\x(2x-7)=0\\x=0\\\text{or}\\2x-7=0\\2x=7\\\\](https://tex.z-dn.net/?f=2x%5E2%3D7x%5C%5C2x%5E2-7x%3D0%5C%5Cx%282x-7%29%3D0%5C%5Cx%3D0%5C%5C%5Ctext%7Bor%7D%5C%5C2x-7%3D0%5C%5C2x%3D7%5C%5C%5C%5C)
![$x=\frac{7}{2} $](https://tex.z-dn.net/?f=%24x%3D%5Cfrac%7B7%7D%7B2%7D%20%24)
(C)
![2x^2+7x-9=0\\\Delta = \sqrt{7^2-4\cdot \:2\left(-9\right)}\\\Delta = \sqrt{7^2+4\cdot \:2\cdot \:9}\\\Delta = \sqrt{121} \\\Delta= 11](https://tex.z-dn.net/?f=2x%5E2%2B7x-9%3D0%5C%5C%5CDelta%20%3D%20%5Csqrt%7B7%5E2-4%5Ccdot%20%5C%3A2%5Cleft%28-9%5Cright%29%7D%5C%5C%5CDelta%20%3D%20%5Csqrt%7B7%5E2%2B4%5Ccdot%20%5C%3A2%5Ccdot%20%5C%3A9%7D%5C%5C%5CDelta%20%3D%20%5Csqrt%7B121%7D%20%5C%5C%5CDelta%3D%2011)
(D)
![2x^2-7x+9=0\\\Delta = \sqrt{\left(-7\right)^2-4\cdot \:2\cdot \:9}\\\\\Delta=\sqrt{-23} \\\Delta=\sqrt{23i}](https://tex.z-dn.net/?f=2x%5E2-7x%2B9%3D0%5C%5C%5CDelta%20%3D%20%5Csqrt%7B%5Cleft%28-7%5Cright%29%5E2-4%5Ccdot%20%5C%3A2%5Ccdot%20%5C%3A9%7D%5C%5C%5C%5C%5CDelta%3D%5Csqrt%7B-23%7D%20%5C%5C%5CDelta%3D%5Csqrt%7B23i%7D)