Answer:
D
Step-by-step explanation:
i did this one
A. 7x
B. 8x-1
C. 6x+12
D. 3x +4
E. 13x-7
7.4 is your final answer, hope that help, one decimal place is the first number after the decimal.
Answer:
![x_{1}=\frac{+3+\sqrt{5} }{2}\\\\x_{2}=\frac{+3-\sqrt{5} }{2}](https://tex.z-dn.net/?f=x_%7B1%7D%3D%5Cfrac%7B%2B3%2B%5Csqrt%7B5%7D%20%7D%7B2%7D%5C%5C%5C%5Cx_%7B2%7D%3D%5Cfrac%7B%2B3-%5Csqrt%7B5%7D%20%7D%7B2%7D)
Step-by-step explanation:
Using:
![x=\frac{-b+-\sqrt{b^{2}-4*a*c} }{2*a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%2B-%5Csqrt%7Bb%5E%7B2%7D-4%2Aa%2Ac%7D%20%7D%7B2%2Aa%7D)
we will have two solutions.
x^2-3x+1=0
So, a=1 b=-3 c=1
![x_{1}=\frac{+3+\sqrt{-3^{2}-4*1*1} }{2*1}\\\\x_{2}=\frac{+3-\sqrt{-3^{2}-4*1*1} }{2*1}](https://tex.z-dn.net/?f=x_%7B1%7D%3D%5Cfrac%7B%2B3%2B%5Csqrt%7B-3%5E%7B2%7D-4%2A1%2A1%7D%20%7D%7B2%2A1%7D%5C%5C%5C%5Cx_%7B2%7D%3D%5Cfrac%7B%2B3-%5Csqrt%7B-3%5E%7B2%7D-4%2A1%2A1%7D%20%7D%7B2%2A1%7D)
We have two solutions:
![x_{1}=\frac{+3+\sqrt{5} }{2}\\\\x_{2}=\frac{+3-\sqrt{5} }{2}](https://tex.z-dn.net/?f=x_%7B1%7D%3D%5Cfrac%7B%2B3%2B%5Csqrt%7B5%7D%20%7D%7B2%7D%5C%5C%5C%5Cx_%7B2%7D%3D%5Cfrac%7B%2B3-%5Csqrt%7B5%7D%20%7D%7B2%7D)