Subtracting the second equation by 18 on both sides, we have xy=-18. Next, we divide both sides by x to get y=-18/x Plugging that into the first equation, we have x+2(-18/x)=9. Multiplying both sides by x, we get x^2-36=9x. After that, we subtract both sides by 9x to get x^2-9x-36=0. Finding 2 numbers that add up to -9 but multiply to -36, we do a bit of guess and check to find the answers to be -12 and 3. Factoring it, we get
x^2-12x+3x-36=x(x-12)+3(x-12)=(x+3)(x-12). To find the x values, we have to find out when 0=(x+3)(x-12). This is simple as when you multiply 0 with anything, it is 0. Therefore, x=-3 and 12. Plugging those into x=-18/y, we get x=-18/y and by multiplying y to both sides, we get xy=-18 and then we can divide both sides by x to get -18/x=y. Plugging -3 in, we get -18/-3=6 and by plugging 12 in we get -18/12=-1.5. Therefore, our points are (-3,6) and (12, -1.5)
Answer:
C.?
Step-by-step explanation:
wheres the pic??
Answer:
The answer to the statement provided is 46.
Answer:
12
Step-by-step explanation:
When n teams play each other once, the total number of games is n(n-1)/2. Since each team played every other one 3 times, the relationship between number of teams (n) and number of games is ...
3(n(n-1)/2) = 198
n(n-1) = 132 = 12·11 . . . . . . multiply by 2/3 and factor
n = 12 . . . . . . n = -11 is also an extraneous solution to this quadratic equation
12 teams participated in this championship.
Some of the possible points using this equation are...
(2,14)
(1,10)
(0,6)
(-1,2)
(-2,-2)
