Im pretty sure is D the mode is increased by 7
Answer:
![\text{The roots of }3x^2+5x-8=0\text{ are }x=1,\frac{-8}{3}](https://tex.z-dn.net/?f=%5Ctext%7BThe%20roots%20of%20%7D3x%5E2%2B5x-8%3D0%5Ctext%7B%20are%20%7Dx%3D1%2C%5Cfrac%7B-8%7D%7B3%7D)
Step-by-step explanation:
a=3, b=-15, c=20
Discriminant can be calculated as
![D=b^2-4ac](https://tex.z-dn.net/?f=D%3Db%5E2-4ac)
![D=(-15)^2-4(3)(20)=225-240=-15](https://tex.z-dn.net/?f=D%3D%28-15%29%5E2-4%283%29%2820%29%3D225-240%3D-15%3C)
The roots are imaginary
The solution is
![x=\frac{-b\pm\sqrt{D}}{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cpm%5Csqrt%7BD%7D%7D%7B2a%7D)
![x=\frac{-(-15)\pm \sqrt{-15}}{2(3)}=\frac{15\pm\sqrt{15}i}{6}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-%28-15%29%5Cpm%20%5Csqrt%7B-15%7D%7D%7B2%283%29%7D%3D%5Cfrac%7B15%5Cpm%5Csqrt%7B15%7Di%7D%7B6%7D)
The roots are not real i.e these are imaginary
a=3, b=5, c=-8
Discriminant can be calculated as
![D=b^2-4ac](https://tex.z-dn.net/?f=D%3Db%5E2-4ac)
![D=(5)^2-4(3)(-8)=25+96=121>0](https://tex.z-dn.net/?f=D%3D%285%29%5E2-4%283%29%28-8%29%3D25%2B96%3D121%3E0)
The roots are real
By quadratic formula method
The solution is
![x=\frac{-b\pm\sqrt{D}}{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cpm%5Csqrt%7BD%7D%7D%7B2a%7D)
![x=\frac{-5)\pm \sqrt{121}}{2(3)}=\frac{-5\pm 11}{6}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-5%29%5Cpm%20%5Csqrt%7B121%7D%7D%7B2%283%29%7D%3D%5Cfrac%7B-5%5Cpm%2011%7D%7B6%7D)
![x=1,\frac{-8}{3}](https://tex.z-dn.net/?f=x%3D1%2C%5Cfrac%7B-8%7D%7B3%7D)
which are required roots.
I choose this method because I can get the solutions directly by substituting the values in formula, and I don't have to guess the possible solutions.
43 since 7-2 =5
And 5 times 7 = 35 for the big box
And the top are 2 little boxes of an area of 4
35+8=43
Step-by-step explanation:
1) 19+i
2) 9-3i
hope this helps bro