I think it is the first and third one
We must find UNIQUE combinations because choosing a,b,c,d... is the same as d,c,b,a...etc. For this type of problem you use the "n choose k" formula...
n!/(k!(n-k)!), n=total number of choices available, k=number of choices made..
In this case:
20!/(10!(20-10)!)
20!/(10!*10!)
184756
Hope this helps!! If u want me to answer any more questions just ask! Have a nice day!
Answer:
d. -2/3x+5
Step-by-step explanation:
Because the line is perpendicular, the slope must be the inverse of the original slope. The inverse of 3/2 is -2/3. To find the b value, you plug (6,1) into the equation y=-2/3x+b
1=-2/3(6)+b
1=-4+b
5=b
The final equation is y=-2/3x+5
your answer would be that the sematry would be vertical semmetry